When a Stablecoin Pool Repriced BIFI

On August 19, ETH rallied roughly 18%. Because most meaningful BIFI liquidity is quoted in WETH, an unchanged BIFI/WETH exchange rate would have delivered a similar dollar gain. Instead, BIFI’s marginal mark on Optimism rose only 13.2%.

Optimism was the only chain with enough USDC/mooBIFI liquidity to support a viable atomic triangle: USDC → mooBIFI → WETH → USDC. Over the next 24 hours, 315 transactions bought 176.03 mooBIFI from the USDC pool and sold the same amount into the WETH pool. The largest matched instance moved 6.05 mooBIFI through the loop in one transaction.

The USDC pool therefore did more than add liquidity. Its presence systematically depreciated mooBIFI against ETH: each arbitrage lifted mooBIFI against USDC while selling it against WETH. This case study reconstructs that flow and measures how a single stablecoin pool transmitted a dollar anchor into the wider BIFI market.

One Asset, Two Numeraires

mooBIFI is a share of Beefy’s BIFI vault. Its BIFI-equivalent value depends on the vault’s price per full share, or PPFS. At the end of this event, one mooBIFI represented 1.35 BIFI.

On Optimism, that share traded in two pools:

• Velodrome V2 WETH/mooBIFI
• Slipstream USDC/mooBIFI

The pools quote the same exposure against different numeraires. Ignoring fees and price impact, consistency requires:

(WETH / mooBIFI) x (USDC / WETH) = USDC / mooBIFI

Suppose the USDC/mooBIFI quote is slow to move while ETH appreciates. One WETH now buys more USDC, so the left-hand side rises even if WETH/mooBIFI is unchanged. Searchers restore the equality by buying mooBIFI with USDC and selling it for WETH. That trade raises mooBIFI versus USDC while lowering it versus WETH.

This is why saying that BIFI is “paired with WETH” is not enough to establish that BIFI will inherit ETH’s dollar return. Its dollar price is an identity:

BIFI / USD = (BIFI / WETH) x (WETH / USD)

In this event, WETH rose 17.5% in the synchronized OP pool path while the OP marginal BIFI-equivalent mark fell 3.62% against WETH. It therefore rose only about 13.2% in dollars.

The canonical route paid 30 basis points in WETH/mooBIFI, 5 basis points in USDC/WETH, and 100 basis points in USDC/mooBIFI. Their multiplicative fee factor was 98.65%, implying a gross cross-rate discrepancy of about 1.37% before price impact and transaction cost.

Reconstructing The Loop Onchain

Every log from the two mooBIFI pools between Optimism blocks 155,749,412 and 155,792,612 was queried, then grouped by transaction hash.

A transaction entered the target set only if it contained:

1. USDC entering the USDC/mooBIFI pool;
2. mooBIFI leaving that pool;
3. the same mooBIFI amount entering the WETH/mooBIFI pool; and
4. WETH leaving the WETH pool.

This deliberately identifies the economic cycle before assuming a particular router. Of the 315 matched transactions, 171 used the canonical three pools exactly once. The remainder used alternate WETH/USDC pools, Uniswap v4 with a native-ETH leg, an RFQ-style connector, or balance-sheet conversion.

Calling every transaction a literal “three-AMM arbitrage” would therefore be wrong. They were all cyclic cross-rate trades, but only 171 had the simplest three-pool implementation.

The matched set contained 19 executing contracts. The largest accounted for 32.29% of mooBIFI volume; the largest three accounted for 60.72%. This was a competitive market response, not one wallet producing a statistical accident.

The Direct Push And The Reflexive Pull

For the WETH/mooBIFI V2 pool, every Sync event reveals the exact reserves immediately after a state change. Pairing those states with each Swap yields the before-and-after marginal quote.

Log price changes make the path attribution additive. If a swap changes the marginal price from p0 to p1, its contribution is:

log(p1 / p0)

Summing those contributions by transaction class separates the stablecoin cycle from the flow that followed it.

The dollar view makes the divergence easier to see. WETH/USD was reconstructed from the canonical OP WETH/USDC pool. The OP WETH/mooBIFI marginal quote was then converted into a BIFI-equivalent dollar mark using fixed end-of-window PPFS, with both dollar prices plotted over the same event timeline.

WETH/USD finished 17.5% higher. The OP BIFI-equivalent mark finished only 13.2% higher, a 4.26 percentage-point shortfall. The first material separation opens alongside the large 15:00 UTC burst of cyclic volume, then widens again as the second burst arrives around 20:00 UTC.

The 315 cyclic transactions contained 320 target WETH/mooBIFI swaps and sold 176.03 mooBIFI into the pool. Along their observed path, those swaps contributed -2,956.20 log basis points, a 25.59% multiplicative decline.

But that was not the end state. As OP became cheap, other traders bought it.

The 266 WETH-funded buys offset 93.1% of the triangle’s negative log impact. Recipient-matched hedges show that part of this response came from cross-chain arbitrageurs buying cheap mooBIFI on OP and selling BIFI-equivalent exposure on Base or Ethereum.

That response makes the event reflexive:

USDC anchor opens cyclic sell
    -> mooBIFI becomes cheap versus WETH elsewhere
    -> cross-chain arbitrageurs buy OP and sell Base/Ethereum
    -> OP partially recovers while pressure propagates outward

The OP marginal quote began at 27.65 mWETH per mooBIFI and finished at 26.64 mWETH, down 3.62% rather than 25.59%.

What Did The Arbitrageurs Actually Extract?

Complete connector economics were reconstructable for 295 of the 315 matched transactions. The remaining 20 used inventory or connector behavior for which public swap deltas do not expose a complete profit. Their profit is therefore left unavailable rather than treated as zero.

Across the classified subset:

• gross cyclic profit was 18.38 mWETH;
• observed OP receipt costs were 3.81 mWETH;
• net profit after those receipt costs was 14.57 mWETH; and
• 294 of 295 transactions remained positive after receipt cost.

Using the block-pinned ETH/USD reference of $2,248.40, that is about $41.33 gross and $32.75 net.

The gross amount is value extracted across the network of AMMs and RFQ counterparties after pool fees. It is not automatically “loss from the USDC/mooBIFI LPs.” Allocating loss to a particular pool requires marking every pool’s inventory against a common fair price after the trade. Concentrated liquidity positions add another layer because different ranges own different amounts of the event.

This is where loss-versus-rebalancing, or LVR, becomes the right framework. LVR compares the LP with a continuously rebalanced benchmark at the external price. The searcher’s gross profit is observable transfer. Full position-level LVR is a separate calculation.

So How Much Did BIFI Holders Lose?

There are three different quantities hiding inside that question.

The first is realized counterparty extraction. For the classified routes, that was about $41.33 gross. This is an actual flow quantity.

The second is a marginal price difference. At the end of the window, the production reference frame had:

• ETH/USD at $2,248.40;
• PPFS at 1.35; and
• observed OP BIFI-equivalent value at about $44.43 per BIFI.

The third is a supply-scaled paper mark: marginal price difference times 80,000 BIFI. That number is tempting and usually misleading because 80,000 BIFI could not execute against a thin marginal quote.

Two counterfactual benchmarks bound the result.

Benchmark 1: OP converges to actual Ethereum

Ethereum is the primary BIFI/WETH price-discovery venue. Its pool had 90 swaps during this event and fell 3.31% versus WETH. BIFI/WETH was therefore not passive even away from the OP stablecoin pool.

If OP had ended exactly at Ethereum’s observed BIFI/WETH marginal price, the OP-equivalent BIFI mark would have been about $44.86: $0.44, or 0.99%, above observed OP. Multiplying that marginal difference by 80,000 produces a paper mark gap of roughly $35,046.

This is the conservative network benchmark, but it may understate the no-USDC-pool effect. Cross-chain arbitrageurs bought the OP weakness and sold on Base or Ethereum, so some of the stablecoin pressure may already have been exported into the Ethereum control price.

Benchmark 2: BIFI/WETH never reprices

The stronger hypothetical holds the opening WETH/mooBIFI ratio constant while ETH rises. Under that passive-WETH-beta assumption, BIFI ends near $46.10, or $1.67 above observed OP. The 80,000-token paper mark gap is approximately $133,641.

This answers the original “what if there were only quiet WETH pools?” question, but the chain data rejects its premise as a description of the real market. Ethereum BIFI/WETH did trade and did fall.

The defensible conclusion is therefore a range, not a point estimate. The stablecoin pool created the observed cyclic sell pressure. Its direct pathwise impact was large. The final holder mark was buffered by cross-chain buyers and confounded by independent—or partly endogenous—BIFI/WETH selling elsewhere.

The $41 gross extraction is realized flow. The $35k-$134k figures are non-executable paper-mark sensitivities. Calling either paper mark “value holders lost” without that distinction would be a market-cap fallacy.

The execution curve shows why. The observed pool was moved along the same constant-product liquidity curve to each counterfactual marginal price, then exact BIFI-equivalent sizes were sold back into WETH with the pool’s 30-basis-point fee.

At 1,000 BIFI, the Ethereum-anchor marginal mark implies $438 of incremental value. The executable difference is only $217. Even that is a controlled single-pool sensitivity: it holds liquidity constant and does not assume other venues would stand still during a sale.

Following the Hedges Across Chains

All 266 WETH-funded mooBIFI buys on OP were screened for matching sales into the Base mooBIFI/WETH and Ethereum BIFI/WETH pools.

The join is conservative. A hedge must have the same swap recipient, occur in the same order, and sell a BIFI-equivalent amount within 2% of the OP buy. Timing alone cannot produce a match. Ethereum BIFI is normalized with the end-of-window PPFS, which introduces a small amount of drift for trades earlier in the day.

For example, this other searcher bought 6.71 mooBIFI on OP, then sold the normalized BIFI-equivalent on Ethereum 42 seconds later. The fixed end-of-window PPFS leaves a 0.53% size difference.

Those 26 proven cross-chain buys account for 72.9% of all WETH-funded buy volume and contributed 2,008.63 positive log basis points—enough to offset 67.9% of the target cycle’s direct negative log impact. The remaining 240 small buys moved 44.37 mooBIFI and cannot be assigned to a cross-chain hedge from these two pools with the same confidence.

How Much of That Buying Was a Response to the Stablecoin Cycle?

The recipient-and-size join proves cross-chain hedge flow. It does not, by itself, prove why each trader acted. Event ordering supplies a second layer of evidence:

• 99.83 of the 119.36 matched mooBIFI—83.6%—was bought within five minutes after an identified USDC cycle;
• that five-minute subset alone was 61.0% of all WETH-funded buy volume; and
• 68.15 matched mooBIFI was bought immediately after a target cycle in the WETH/mooBIFI pool’s event order.

This is the endogenous feedback loop visible in the data: the stablecoin cycle sold mooBIFI into WETH, the cheaper OP quote attracted cross-chain buyers, and those buyers exported the basis by selling on Base or Ethereum. The evidence does not support attributing all 119.36 mooBIFI to the USDC pool—some arrived long after the most recent cycle—but 99.83 mooBIFI has both an identified cross-chain hedge and tight event-time proximity.

The 42-second example is also a reminder that this is non-atomic cross-chain arbitrage. Exact recipient and size evidence can establish a strong link, but the delay between legs remains inventory risk rather than atomic execution.

What the Pools Earned

The swaps also reveal the gross fee budget, although not yet each LP position’s return.

The target cycles paid 9,797.12 USDC into the 1% USDC/mooBIFI pool, implying $97.97 of gross swap fees. They also sold 176.03 mooBIFI into the 30 bp WETH/mooBIFI pool, implying 0.53 mooBIFI of gross fees, worth about $31.64 at the reference mark. Combined, the two mooBIFI pools charged about $129.61 on the target legs before any protocol split or position-level allocation.

Across all swaps in the day—not only the target cycles—the WETH/mooBIFI pool’s gross fee inputs were 12.98 mWETH and 0.56 mooBIFI. The USDC/mooBIFI pool’s were 167.63 USDC and 0.04 mooBIFI.

This still does not answer position-level LVR. Determining whether a particular LP’s fees compensated for adverse selection requires every position’s active liquidity and tick range, fee-growth checkpoints, ownership changes, and the protocol-fee share at each swap. Likewise, a true all-venue exact-size curve requires synchronized tick liquidity—not just the marginal swap prices—on OP, Base, and Ethereum. Those are now the two genuinely unresolved measurements, rather than a generic list of future work.

The event already demonstrates something more general. A small pool quoted in a different numeraire can become a transmission channel during a macro move. Its TVL does not bound its influence to its own venue. Arbitrage can propagate its price through another pool, attract cross-chain hedging, and export the pressure into the market that was supposed to be the reference.

Liquidity fragmentation is not just several prices waiting to converge. It is the mechanism that decides which price gets carried where—and who gets paid to carry it.