Managed Fund: reject Pyth prices with a wide confidence interval

load_price in all three copies (Anchor v2, Anchor v1, Quasar) now reads
the PriceUpdateV2 `conf` field (offset 81) and rejects a price whose
interval exceeds MAX_CONFIDENCE_BPS (100 bps, 1% of the price) with the
new OracleConfidenceTooWide error. Deposit prices shares and rebalance
sets its swap floor from the oracle, so a wide band moved value between
depositors or loosened the floor. Withdraw reads no price and still pays
out in kind.

test_wide_confidence_price_rejected in each copy widens NVDAx's band to
2% and asserts deposit and rebalance fail, withdraw succeeds, and a band
of exactly 1% is accepted. The app IDLs gain the error; READMEs and
CHANGELOGs follow.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013ji7D1gLxYnd1cdd6NMXQL

Author: claude

CHANGELOG.md

@@ -4,6 +4,18 @@ All notable changes to this repository are documented here.
 
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
 
+## [2026-10-03] - Managed Fund rejects wide-confidence prices
+
+### Fixed
+
+- `finance/managed-fund` (Anchor v2, Anchor v1, Quasar) ignored the
+  confidence interval on its Pyth prices. `load_price` now rejects a price
+  whose interval exceeds 1% of the price (`MAX_CONFIDENCE_BPS`, new
+  `OracleConfidenceTooWide` error), so deposit and rebalance are refused while
+  publishers disagree; withdraw reads no price and still pays out in kind.
+  Tested by `test_wide_confidence_price_rejected` in each copy. The web apps'
+  IDLs gain the error.
+
 ## [2026-10-03] - Fundraiser: `close_contributor` is `close_contribution`
 
 ### Changed

finance/managed-fund/anchor-v1/CHANGELOG.md

@@ -1,5 +1,9 @@
 # Changelog
 
+## 2026-10-03
+
+- **Prices with a wide confidence interval are rejected.** Pyth reports each price with a confidence interval (`conf`, offset 81), and `load_price` ignored it, so a price the publishers disagreed on by several percent was used as if it were exact. Deposits price shares from that price and rebalance sets its swap floor from it, so a wide band moves value between depositors or loosens the floor by the same amount. `load_price` now rejects a price whose interval exceeds `MAX_CONFIDENCE_BPS` (100 bps, 1% of the price) with the new `OracleConfidenceTooWide` error. `withdraw` reads no price and is unaffected, so investors can still leave in kind. The limit is a program constant, like the 60-second staleness window; prop-amm and perpetual-futures store theirs per market. Tested by `test_wide_confidence_price_rejected`. The web app's IDL gains the error.
+
 ## 2026-10-01
 
 - **Valuation scales by each asset's decimals and each feed's exponent.** The fund valued an asset as `amount × price / 10⁸`, which is right only when the asset has USDC's 6 decimals and its Pyth feed has exponent −8, and nothing checked either. An eight-decimal asset would have been valued 100 times too high, so a later depositor would have bought almost no shares; Pyth's US equity feeds use exponent −5, a further factor of 1,000. `load_price` now reads the exponent (offset 89) and returns an `OraclePrice`, `AssetConfig` records the mint's `decimals` and `Fund` the USDC mint's `usdc_decimals`, and `deposit` and `rebalance` value and size swaps with `asset_value_in_usdc` and `usdc_to_asset_amount`, which scale by `10^(usdc_decimals + exponent − asset_decimals)`. `PYTH_PRICE_PRECISION` is removed. The mock router's `usdc_per_token` is now USDC minor units per whole token, and its swaps scale by the asset mint's decimals. Tested by `test_valuation_scales_by_decimals_and_exponent`, which runs the story with an eight-decimal TSLAx on an exponent −5 feed.

finance/managed-fund/anchor-v1/README.md

@@ -33,7 +33,7 @@ Because the asset set is dynamic, `deposit` must value *every* asset. The assets
 
 Referencing every asset has a transaction-size cost: `deposit` pulls in `14 + 5N` accounts and `withdraw` `10 + 4N`, where `N` is the asset count. That stays within Solana's 128-account transaction lock limit at the `MAX_ASSETS` cap of 16 (94 accounts for `deposit`), but a basket beyond roughly three assets no longer fits a legacy transaction's 1232-byte limit, so the client must send a v0 transaction with an [Address Lookup Table](https://docs.anza.xyz/proposals/versioned-transactions).
 
-Prices come from [Pyth Network](https://pyth.network/) `PriceUpdateV2` accounts. A 60-second staleness window is enforced; zero or negative prices are rejected, and so is any price posted at or before the last cluster restart (`PricePredatesRestart`), which the seconds check alone cannot catch after a halt.
+Prices come from [Pyth Network](https://pyth.network/) `PriceUpdateV2` accounts. A 60-second staleness window is enforced; zero or negative prices are rejected, and so is any price posted at or before the last cluster restart (`PricePredatesRestart`), which the seconds check alone cannot catch after a halt. A price whose confidence interval is wider than 1% of the price (`MAX_CONFIDENCE_BPS`, 100) is rejected too (`OracleConfidenceTooWide`): deposits price shares from the oracle and rebalance sets its swap floor from it, so a price the publishers disagree on by more than a typical slippage tolerance is not one to trade on. `withdraw` reads no price, so investors can always leave in kind while deposits and rebalances wait for the band to narrow.
 
 ### Shares
 
@@ -161,7 +161,7 @@ cargo build-sbf --manifest-path programs/managed-fund/Cargo.toml
 cargo test --manifest-path programs/managed-fund/Cargo.toml
 ```
 
-Tests live in `programs/managed-fund/tests/managed_fund.rs` and use [LiteSVM](https://github.com/LiteSVM/litesvm). Both `.so` files are loaded from `target/deploy/`, so build before testing. The suite covers the full lifecycle end to end (deposit with auto-deployment, a price move, rebalance back to target, a second depositor priced at the new NAV, a year's fee, in-kind withdrawal), retiring an asset with `set_weight` and reallocating to reopen deposits, and the rejection paths: unapproved asset, weight overflow, over-cap fee and slippage, oracle-bounded deposit slippage, an under-allocated fund, non-manager `set_weight`, unregistered router, and incomplete asset accounts on deposit and rebalance. The rebalance tests sign as a stranger, since anyone may call it: `test_rebalance_refuses_fund_at_target`, `test_rebalance_refuses_drift_below_threshold` and `test_rebalance_cannot_churn` check that a fund at its targets, or within its threshold, or just rebalanced, cannot be traded; `test_rebalance_refuses_buying_overweight_asset`, `test_rebalance_sells_retired_asset` and `test_initialize_rejects_threshold_out_of_range` cover the rest of its rules. `test_valuation_scales_by_decimals_and_exponent` runs the story with an eight-decimal TSLAx priced by an exponent −5 feed and gets the same share counts. `test_full_lifecycle` checks after every step that the recorded holdings equal the vaults' balances. `test_donation_does_not_inflate_share_price` runs the first-depositor attack (a one-minor-unit deposit, a 1,000 USDC transfer straight into the USDC vault, then a 1,000 USDC deposit with no `minimum_shares` floor) and checks the victim gets exactly the shares they would have got without the donation. `test_deposit_rejects_leg_that_buys_nothing` and `test_rebalance_ignores_donations` pin the other two guards: the second checks that donated tokens can neither force a rebalance nor be spent by one.
+Tests live in `programs/managed-fund/tests/managed_fund.rs` and use [LiteSVM](https://github.com/LiteSVM/litesvm). Both `.so` files are loaded from `target/deploy/`, so build before testing. The suite covers the full lifecycle end to end (deposit with auto-deployment, a price move, rebalance back to target, a second depositor priced at the new NAV, a year's fee, in-kind withdrawal), retiring an asset with `set_weight` and reallocating to reopen deposits, and the rejection paths: unapproved asset, weight overflow, over-cap fee and slippage, oracle-bounded deposit slippage, an under-allocated fund, non-manager `set_weight`, unregistered router, and incomplete asset accounts on deposit and rebalance. The rebalance tests sign as a stranger, since anyone may call it: `test_rebalance_refuses_fund_at_target`, `test_rebalance_refuses_drift_below_threshold` and `test_rebalance_cannot_churn` check that a fund at its targets, or within its threshold, or just rebalanced, cannot be traded; `test_rebalance_refuses_buying_overweight_asset`, `test_rebalance_sells_retired_asset` and `test_initialize_rejects_threshold_out_of_range` cover the rest of its rules. `test_valuation_scales_by_decimals_and_exponent` runs the story with an eight-decimal TSLAx priced by an exponent −5 feed and gets the same share counts. `test_wide_confidence_price_rejected` widens NVDAx's confidence interval to 2% of its price and checks that deposit and rebalance fail with `OracleConfidenceTooWide`, that withdraw still pays out in kind, and that a band of exactly 1% is accepted. `test_full_lifecycle` checks after every step that the recorded holdings equal the vaults' balances. `test_donation_does_not_inflate_share_price` runs the first-depositor attack (a one-minor-unit deposit, a 1,000 USDC transfer straight into the USDC vault, then a 1,000 USDC deposit with no `minimum_shares` floor) and checks the victim gets exactly the shares they would have got without the donation. `test_deposit_rejects_leg_that_buys_nothing` and `test_rebalance_ignores_donations` pin the other two guards: the second checks that donated tokens can neither force a rebalance nor be spent by one.
 
 ## FAQ
 

finance/managed-fund/anchor-v1/app/src/idl/managed_fund.json

@@ -1047,6 +1047,11 @@
       "code": 6031,
       "name": "NotUnderweight",
       "msg": "The asset to buy is not below its target weight"
+    },
+    {
+      "code": 6032,
+      "name": "OracleConfidenceTooWide",
+      "msg": "Pyth price confidence interval is too wide to trust"
     }
   ],
   "types": [

finance/managed-fund/anchor-v1/programs/managed-fund/src/error.rs

@@ -66,4 +66,6 @@ pub enum FundError {
     DriftBelowThreshold,
     #[msg("The asset to buy is not below its target weight")]
     NotUnderweight,
+    #[msg("Pyth price confidence interval is too wide to trust")]
+    OracleConfidenceTooWide,
 }

finance/managed-fund/anchor-v1/programs/managed-fund/src/oracle.rs

@@ -6,6 +6,8 @@ use crate::error::FundError;
 /// Byte offset of `price` (i64) inside a Pyth PriceUpdateV2 account:
 ///   8 discriminator + 32 write_authority + 1 verification_level + 32 feed_id = 73
 const PYTH_PRICE_OFFSET: usize = 73;
+/// Byte offset of `conf` (u64), the confidence interval: +8 bytes after price.
+const PYTH_CONF_OFFSET: usize = PYTH_PRICE_OFFSET + 8; // 81
 /// Byte offset of `exponent` (i32): price(8) + conf(8) = +16 bytes after price.
 const PYTH_EXPONENT_OFFSET: usize = PYTH_PRICE_OFFSET + 8 + 8; // 89
 /// Byte offset of `publish_time` (i64):
@@ -16,6 +18,12 @@ const PYTH_PUBLISH_TIME_OFFSET: usize = PYTH_PRICE_OFFSET + 8 + 8 + 4; // 93
 const PYTH_POSTED_SLOT_OFFSET: usize = PYTH_PUBLISH_TIME_OFFSET + 8 + 8 + 8 + 8; // 125
 /// Prices older than this (seconds) are rejected.
 const MAX_PRICE_AGE_SECONDS: i64 = 60;
+/// Widest confidence interval accepted, in basis points of the price (1%).
+/// Deposits price shares and rebalance sets its swap floor from the Pyth
+/// price, so a price that may be off by more than a typical 1% slippage
+/// tolerance would quietly widen that tolerance. Major feeds usually quote
+/// well under 0.1%; a band past 1% means the publishers disagree.
+const MAX_CONFIDENCE_BPS: u128 = 100;
 
 /// SPL token account layout: amount is a u64 at bytes 64..72. The base layout is
 /// shared by the Classic Token Program and the Token Extensions Program, so this
@@ -35,8 +43,8 @@ pub struct OraclePrice {
     pub exponent: i32,
 }
 
-/// Returns `(price, exponent, publish_time, posted_slot)`.
-fn read_pyth_raw(account_data: &[u8]) -> Result<(i64, i32, i64, u64)> {
+/// Returns `(price, conf, exponent, publish_time, posted_slot)`.
+fn read_pyth_raw(account_data: &[u8]) -> Result<(i64, u64, i32, i64, u64)> {
     if account_data.len() < PYTH_POSTED_SLOT_OFFSET + 8 {
         return err!(FundError::InvalidPriceFeed);
     }
@@ -45,6 +53,11 @@ fn read_pyth_raw(account_data: &[u8]) -> Result<(i64, i32, i64, u64)> {
             .try_into()
             .map_err(|_| FundError::InvalidPriceFeed)?,
     );
+    let conf = u64::from_le_bytes(
+        account_data[PYTH_CONF_OFFSET..PYTH_CONF_OFFSET + 8]
+            .try_into()
+            .map_err(|_| FundError::InvalidPriceFeed)?,
+    );
     let exponent = i32::from_le_bytes(
         account_data[PYTH_EXPONENT_OFFSET..PYTH_EXPONENT_OFFSET + 4]
             .try_into()
@@ -60,11 +73,12 @@ fn read_pyth_raw(account_data: &[u8]) -> Result<(i64, i32, i64, u64)> {
             .try_into()
             .map_err(|_| FundError::InvalidPriceFeed)?,
     );
-    Ok((price, exponent, publish_time, posted_slot))
+    Ok((price, conf, exponent, publish_time, posted_slot))
 }
 
 /// Validate a price feed account against the one the fund registered, then
 /// return its positive, fresh price. `now` is the current unix timestamp.
+/// A price whose confidence interval exceeds `MAX_CONFIDENCE_BPS` is rejected.
 /// A price posted at or before the last cluster restart is rejected too.
 pub fn load_price(
     price_feed: &AccountInfo,
@@ -74,9 +88,19 @@ pub fn load_price(
     require_keys_eq!(price_feed.key(), *expected_key, FundError::InvalidPriceFeed);
 
     let data = price_feed.try_borrow_data()?;
-    let (price, exponent, publish_time, posted_slot) = read_pyth_raw(&data)?;
+    let (price, conf, exponent, publish_time, posted_slot) = read_pyth_raw(&data)?;
 
     require!(price > 0, FundError::NegativePrice);
+
+    // Reject a price the oracle itself is unsure of: the confidence interval,
+    // as a fraction of the price, must not exceed MAX_CONFIDENCE_BPS. `conf`
+    // shares the price's exponent, so the ratio needs no scaling, and in u128
+    // neither product can overflow.
+    require!(
+        (conf as u128) * 10_000 <= (price as u128) * MAX_CONFIDENCE_BPS,
+        FundError::OracleConfidenceTooWide
+    );
+
     require!(
         now.checked_sub(publish_time)
             .ok_or(FundError::MathOverflow)?

finance/managed-fund/anchor-v1/programs/managed-fund/tests/managed_fund.rs

@@ -47,9 +47,10 @@ fn derive_ata(wallet: &Pubkey, mint: &Pubkey) -> Pubkey {
 }
 
 /// Mock PriceUpdateV2 layout (see pyth-solana-receiver-sdk): price i64 at 73,
-/// publish_time i64 at 93, posted_slot u64 at 125. Exponent -8.
+/// conf u64 at 81, publish_time i64 at 93, posted_slot u64 at 125. Exponent -8.
 fn build_mock_price_update_account(
     price: i64,
+    confidence: u64,
     exponent: i32,
     publish_time: i64,
     posted_slot: u64,
@@ -61,7 +62,7 @@ fn build_mock_price_update_account(
     data.push(1u8);
     data.extend_from_slice(&[0xEFu8; 32]);
     data.extend_from_slice(&price.to_le_bytes());
-    data.extend_from_slice(&100_000u64.to_le_bytes());
+    data.extend_from_slice(&confidence.to_le_bytes());
     data.extend_from_slice(&exponent.to_le_bytes());
     data.extend_from_slice(&publish_time.to_le_bytes());
     data.extend_from_slice(&(publish_time - 1).to_le_bytes());
@@ -82,7 +83,20 @@ fn set_price_feed_posted_at(svm: &mut LiteSVM, key: Pubkey, price: i64, posted_s
 
 /// Write a Pyth feed with its own exponent: Pyth's US equity feeds use -5.
 fn write_price_feed(svm: &mut LiteSVM, key: Pubkey, price: i64, exponent: i32, posted_slot: u64) {
-    let data = build_mock_price_update_account(price, exponent, PUBLISH_TIME, posted_slot);
+    write_price_feed_with_confidence(svm, key, price, DEFAULT_CONFIDENCE, exponent, posted_slot);
+}
+
+/// Write a Pyth feed with its own confidence interval, in the price's units.
+fn write_price_feed_with_confidence(
+    svm: &mut LiteSVM,
+    key: Pubkey,
+    price: i64,
+    confidence: u64,
+    exponent: i32,
+    posted_slot: u64,
+) {
+    let data =
+        build_mock_price_update_account(price, confidence, exponent, PUBLISH_TIME, posted_slot);
     let rent = svm.minimum_balance_for_rent_exemption(data.len());
     svm.set_account(
         key,
@@ -98,6 +112,8 @@ fn write_price_feed(svm: &mut LiteSVM, key: Pubkey, price: i64, exponent: i32, p
 }
 
 const PUBLISH_TIME: i64 = 1_700_000_000;
+/// A tight confidence interval, $0.001 at exponent -8, far inside the 1% limit.
+const DEFAULT_CONFIDENCE: u64 = 100_000;
 const TOKEN_DECIMALS: u8 = 6;
 const SECONDS_PER_YEAR: i64 = 31_536_000;
 
@@ -2057,3 +2073,68 @@ fn test_valuation_scales_by_decimals_and_exponent() {
     assert_eq!(read_fund(&ctx).asset_holdings[1], 4_320_000);
     assert_holdings_match_vaults(&ctx);
 }
+
+/// A price the oracle is unsure of is not traded on. With NVDAx's confidence
+/// interval at 2% of its price, past the 1% limit, deposit and rebalance both
+/// refuse, but withdraw still pays out in kind: it reads no price, so investors
+/// can always leave. A band of exactly 1% is accepted.
+#[test]
+fn test_wide_confidence_price_rejected() {
+    let mut ctx = setup_full();
+    standard_fund(&mut ctx);
+
+    // Alice deposits 900 USDC: 1.44 TSLAx + 3.0 NVDAx at 40/60.
+    let alice = fund_user(&mut ctx, 900_000_000);
+    do_deposit(&mut ctx, &alice, 900_000_000, 1);
+
+    // NVDAx rises to $200, so the fund has drifted and needs a rebalance. Then
+    // its feed reports a $4 confidence interval: 2% of the price.
+    set_nvda_price(&mut ctx, 20_000_000_000, 200_000_000);
+    write_price_feed_with_confidence(
+        &mut ctx.svm,
+        ctx.price_feed_nvda,
+        20_000_000_000,
+        400_000_000,
+        -8,
+        1,
+    );
+
+    let bob = fund_user(&mut ctx, 480_000_000);
+    let ix = deposit_instruction(&ctx, &bob, 480_000_000, 1, deposit_remaining(&ctx));
+    assert_program_error(
+        send_transaction_from_instructions(&mut ctx.svm, vec![ix], &[&bob], &bob.pubkey()),
+        FundError::OracleConfidenceTooWide,
+        "a deposit priced from a wide-confidence feed must fail",
+    );
+    assert_program_error(
+        try_rebalance(&mut ctx, 1, 0),
+        FundError::OracleConfidenceTooWide,
+        "a rebalance priced from a wide-confidence feed must fail",
+    );
+
+    // Withdraw reads no price: Alice takes half her shares out in kind.
+    do_withdraw(&mut ctx, &alice, 450_000_000, 0);
+    assert_eq!(
+        get_token_account_balance(&ctx.svm, &derive_ata(&alice.pubkey(), &ctx.tsla_mint)).unwrap(),
+        720_000
+    );
+    assert_eq!(
+        get_token_account_balance(&ctx.svm, &derive_ata(&alice.pubkey(), &ctx.nvda_mint)).unwrap(),
+        1_500_000
+    );
+
+    // A $2 interval is exactly 1% of the price, which is accepted: the
+    // rebalance sells 0.06 NVDAx for 12 USDC and buys 0.048 TSLAx.
+    write_price_feed_with_confidence(
+        &mut ctx.svm,
+        ctx.price_feed_nvda,
+        20_000_000_000,
+        200_000_000,
+        -8,
+        1,
+    );
+    do_rebalance(&mut ctx, 1, 0);
+    assert_eq!(read_fund(&ctx).asset_holdings[0], 768_000);
+    assert_eq!(read_fund(&ctx).asset_holdings[1], 1_440_000);
+    assert_holdings_match_vaults(&ctx);
+}

finance/managed-fund/anchor/CHANGELOG.md

@@ -1,5 +1,9 @@
 # Changelog
 
+## 2026-10-03
+
+- **Prices with a wide confidence interval are rejected.** Pyth reports each price with a confidence interval (`conf`, offset 81), and `load_price` ignored it, so a price the publishers disagreed on by several percent was used as if it were exact. Deposits price shares from that price and rebalance sets its swap floor from it, so a wide band moves value between depositors or loosens the floor by the same amount. `load_price` now rejects a price whose interval exceeds `MAX_CONFIDENCE_BPS` (100 bps, 1% of the price) with the new `OracleConfidenceTooWide` error. `withdraw` reads no price and is unaffected, so investors can still leave in kind. The limit is a program constant, like the 60-second staleness window; prop-amm and perpetual-futures store theirs per market. Tested by `test_wide_confidence_price_rejected`. The web app's IDL gains the error.
+
 ## 2026-10-01
 
 - **Valuation scales by each asset's decimals and each feed's exponent.** The fund valued an asset as `amount × price / 10⁸`, which is right only when the asset has USDC's 6 decimals and its Pyth feed has exponent −8, and nothing checked either. An eight-decimal asset would have been valued 100 times too high, so a later depositor would have bought almost no shares; Pyth's US equity feeds use exponent −5, a further factor of 1,000. `load_price` now reads the exponent (offset 89) and returns an `OraclePrice`, `AssetConfig` records the mint's `decimals` and `Fund` the USDC mint's `usdc_decimals`, and `deposit` and `rebalance` value and size swaps with `asset_value_in_usdc` and `usdc_to_asset_amount`, which scale by `10^(usdc_decimals + exponent − asset_decimals)`. `PYTH_PRICE_PRECISION` is removed. The mock router's `usdc_per_token` is now USDC minor units per whole token, and its swaps scale by the asset mint's decimals. Tested by `test_valuation_scales_by_decimals_and_exponent`, which runs the story with an eight-decimal TSLAx on an exponent −5 feed.