low CROSS_SURFACE_PRICE_MIX

AAPL: off-chain share price and on-chain token price differ by 0.057%

subject AAPL (0xaF3D76f1834A1d425780943C99Ea8A608f8a93f9) · methodology assay-rh-v0.2.0 · detected 2026-09-21T21:00:41.000Z

The Chainlink feed returns a multiplier-adjusted TOKEN price (339.2419), while Robinhood's REST /prices endpoint returns the RAW UNDERLYING share price (mid 338.6550). These are different quantities related by uiMultiplier(): underlying x 1.000566080 = 338.8467 (residual 0.117%, attributable to bid/ask spread and quote timing). Valuing balanceOf() with an off-chain share price, or computing a premium/discount between an on-chain token price and an off-chain share price, produces a phantom error of 0.057%.

Impact

5.66 bps · 0.0566%

feed 339.2419 vs underlying-mid 338.6550 x multiplier 1.000566080 = 338.8467

Evidence — 2/2 citations re-fetched and byte-compared

mismatched 0 · pruned 0 · verified 2026-09-21T21:00:50.219Z

uiMultiplier() == 1000566080061092436

chain 4663 · block 69103532 · uiMultiplier()
0xaF3D76f1834A1d425780943C99Ea8A608f8a93f9

0x0000000000000000000000000000000000000000000000000de2b98c7058b254

latestRoundData().answer == 33924192943

chain 4663 · block 69103532 · latestRoundData()
0x6B22A786bAa607d76728168703a39Ea9C99f2cD0

0x000000000000000000000000000000000000000000000001000000000000028a00000000000000000000000000000000000000000000000000000007e60a1aaf000000000000000000000000000000000000000000000000000000006ab15e92000000000000000000000000000000000000000000000000000000006ab15e9e000000000000000000000000000000000000000000000001000000000000028a

Off-chain inputs — NOT covered by the byte-verified guarantee

The citations above are re-fetched from chain state and byte-compared. The values below cannot be, because they do not live on chain. They are listed so you can tell the difference.

underlying share bid/ask used for the mid 338.6550 (not multiplier-adjusted)

fetched 2026-09-21T21:00:41.465821185Z
https://api.robinhood.com/rhj/prices/AAPL

Reproduce this yourself:

cast call 0xaF3D76f1834A1d425780943C99Ea8A608f8a93f9 "uiMultiplier()" \
  --block 69103532 \
  --rpc-url https://rpc.mainnet.chain.robinhood.com

Note: the public RPC prunes state within roughly 1k–10k blocks, so an older block may no longer be served. That makes a citation unchecked here, not disproven — ASSAY reports those two cases separately and never publishes a finding whose citation contradicts chain state.