low CROSS_SURFACE_PRICE_MIX

NVDA: off-chain share price and on-chain token price differ by 0.078%

subject NVDA (0xd0601CE157Db5bdC3162BbaC2a2C8aF5320D9EEC) · methodology assay-rh-v0.2.0 · detected 2026-09-21T20:56:31.000Z

The Chainlink feed returns a multiplier-adjusted TOKEN price (227.3061), while Robinhood's REST /prices endpoint returns the RAW UNDERLYING share price (mid 226.9500). These are different quantities related by uiMultiplier(): underlying x 1.000775159 = 227.1259 (residual 0.079%, 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 0.078%.

Impact

7.75 bps · 0.0775%

feed 227.3061 vs underlying-mid 226.9500 x multiplier 1.000775159 = 227.1259

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

mismatched 0 · pruned 0 · verified 2026-09-21T20:56:39.614Z

uiMultiplier() == 1000775159164630595

chain 4663 · block 69101039 · uiMultiplier()
0xd0601CE157Db5bdC3162BbaC2a2C8aF5320D9EEC

0x0000000000000000000000000000000000000000000000000de377b4760af643

latestRoundData().answer == 22730606190

chain 4663 · block 69101039 · latestRoundData()
0x379EC4f7C378F34a1B47E4F3cbeBCbAC3E8E9F15

0x0000000000000000000000000000000000000000000000010000000000000432000000000000000000000000000000000000000000000000000000054ad9866e000000000000000000000000000000000000000000000000000000006ab18a8b000000000000000000000000000000000000000000000000000000006ab18a980000000000000000000000000000000000000000000000010000000000000432

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 226.9500 (not multiplier-adjusted)

fetched 2026-09-21T20:56:35.865508472Z
https://api.robinhood.com/rhj/prices/NVDA

Reproduce this yourself:

cast call 0xd0601CE157Db5bdC3162BbaC2a2C8aF5320D9EEC "uiMultiplier()" \
  --block 69101039 \
  --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.