Bybit Halves TradFi RPI Rebates as Taker Access Widens

Bybit’s TradFi RPI update pays approved makers less while letting more taker instructions reach their protected inventory, making the router the immediate winner and the liquidity supplier the payer. The counterparties are distinct: an enrolled market maker posts RPI-only inventory; a trader or API router chooses whether and how aggressively to execute; Bybit’s matching engine assigns priority and pays the rebate. The maker earns spread plus incentive but carries inventory risk and adverse selection when a faster counterparty trades just before the reference market moves.

What changes in Bybit’s TradFi RPI maker rebate?

The enhanced maker rebate falls from 0.5 basis points to 0.25 basis points on September 10 at 08:00 UTC. A negative maker fee means Bybit pays the qualifying supplier: on $10 million of executed RPI notional, the payment drops from $500 to $250. Market makers outside the TradFi Perps Liquidity Incentive Program remain at zero.

That is a clean transfer of economics to the venue. Bybit keeps half of the former subsidy while asking the same specialist pool to quote post-only orders that sit behind regular API liquidity at an identical price. Makers can still justify the queue because RPI flow is segmented and a 50-millisecond delay protects eligible quotes from some latency arbitrage, but the buffer against toxic fills is now $25 smaller per $1 million traded.

How do the RPI matching changes affect execution?

The matching change expands usable RPI depth from market IOC/FOK orders to limit IOC and FOK orders as well. A router can therefore opt into RPI while imposing a worst acceptable price, instead of using a market instruction whose protection is controlled by the venue’s slippage guard.

• Maker: supplies post-only RPI inventory, receives the reduced rebate and absorbs inventory and selection risk.
• Taker: sets rpiTakerAccess, price and urgency; IOC permits a partial fill, while FOK demands the full size immediately.
• Venue: matches regular API liquidity first at the same price; RPI wins only at a strictly better price or after that public pool is exhausted.

Rate limits and price-time treatment are otherwise unchanged. The 50-millisecond delay now applies only on RPI-eligible symbols, removing needless waiting from symbols where protected liquidity cannot fill the order.

Will better matching survive without maker incentives?

The feature should survive a smaller rebate on active symbols, but its depth will not survive the exit of a dominant supplier. Limit IOC and FOK instructions improve access to inventory; they do not create it. If spread capture and the protected-flow advantage cover adverse selection after the 0.25-basis-point cut, makers stay. If the subsidy disappears or one large quoter leaves, displayed RPI depth can thin abruptly and FOK rejection rates will rise. Bybit’s recent removal of RPI eligibility from selected TradFi contracts also shows that symbol coverage is a venue-controlled dependency, not a permanent execution right.

What should API builders change in their router?

Builders should make RPI an optional branch beside the standard order-book route, not the route itself. The existing order endpoint already reaches the regular book; on an eligible symbol, add RPI access and prefer a limit IOC with an explicit price bound. Use FOK only when partial execution is operationally worse than no trade, record RPI matched quantity separately, and retry against ordinary liquidity when protected depth disappears. Keep collateral sized for the standard route because RPI orders share normal margin requirements. The verdict is straightforward: takers gain tighter control and more reachable liquidity, Bybit saves subsidy, and makers must now prove that protected flow is worth half the payment.