Speed Bump

The defining feature of a speed bump is its asymmetric application. The delay is imposed only on incoming aggressive orders (marketable orders that take liquidity), while resting passive orders (limit orders that provide liquidity) receive real-time market data and can cancel or reprice without delay. This asymmetry specifically targets latency arbitrage strategies that profit from racing to stale quotes before a venue can update them. The delay is typically measured in microseconds (e.g., 350 microseconds on IEX) and is implemented via a coiled fiber optic cable or a software-based delay buffer in the order gateway.

The most famous implementation of a speed bump is on the IEX Exchange, founded by Brad Katsuyama and featured in Michael Lewis's book Flash Boys. IEX's speed bump consists of a 38-mile coiled fiber optic cable that introduces a 350-microsecond delay on all incoming orders before they reach the matching engine. Outgoing market data bypasses the coil, giving resting orders a speed advantage. This physical implementation ensures the delay is deterministic and cannot be bypassed through software optimization. IEX received SEC approval as a national securities exchange in 2016 after a contentious battle with incumbent exchanges.

Speed bumps have generated significant controversy in market structure debates. Proponents argue they level the playing field by preventing technological arms races and protecting long-term investors from predatory HFT strategies. Critics, including major exchanges like NYSE and Nasdaq, contend that speed bumps fragment liquidity, create a two-tiered market, and violate the principle of price-time priority by artificially advantaging certain order types. The SEC has allowed speed bumps but has scrutinized whether they comply with Regulation NMS and the Order Protection Rule, which requires trades to occur at the best available price across all venues.

A speed bump fundamentally alters the queue position dynamics of a limit order book. In a traditional price-time priority market, the first order at a given price level is matched first. By delaying aggressive orders while allowing passive orders to cancel instantly, the speed bump effectively gives resting liquidity providers a last-mover advantage. This reduces the risk of adverse selection for market makers, encouraging tighter spreads and deeper liquidity. However, it also means that a trader who is first to respond to new information may be disadvantaged, raising questions about whether speed bumps distort the price discovery process.

Beyond IEX, several global venues have adopted speed bump mechanisms with varying designs:

• TSX Alpha Exchange (Canada): Introduced a randomized 1-3 millisecond delay on incoming orders
• NYSE American: Proposed a 350-microsecond speed bump but withdrew the plan after regulatory pushback
• Cboe EDGA: Implemented a liquidity provider protection delay
• London Stock Exchange: Explored a speed bump for its SETS order book
• Eurex: Uses a passive liquidity protection delay in certain products Each implementation balances the trade-off between protecting liquidity providers and maintaining fair access for all market participants.

A high-frequency strategy that exploits microscopic time differences between a venue's proprietary data feed and the slower consolidated SIP feed. Traders detect price changes on a fast direct feed and trade against stale quotes on other venues before they update.

• Relies on speed asymmetry measured in microseconds
• Speed bumps neutralize this advantage by delaying aggressive orders
• Primary target of IEX's 350-microsecond delay

The risk that a trade counterparty possesses superior information, causing a liquidity provider to transact at a disadvantageous price that immediately moves against them. In high-frequency markets, this often manifests as being picked off by faster traders reacting to public information.

• Market makers widen spreads to compensate for this risk
• Speed bumps reduce adverse selection by giving resting orders time to cancel
• Key driver of order flow toxicity metrics

A fee structure where exchanges pay a rebate to traders who provide liquidity via resting limit orders (makers) and charge a fee to traders who take liquidity with marketable orders (takers). This model incentivizes order book depth.

• Creates economic tension with speed bumps that protect makers
• Inverted venues reverse the fee structure to attract takers
• Speed bumps alter the cost-benefit calculus of liquidity provision

The ordinal rank of a resting limit order within the price-time priority stack at a specific price level. Orders at the front of the queue are matched first when contra-side liquidity arrives.

• HFTs race to achieve top queue position on price moves
• Speed bumps reduce the value of pure speed in queue competition
• Encourages price improvement over latency optimization

The practice of placing trading servers physically within an exchange's data center to minimize network latency between the order gateway and matching engine. This infrastructure investment is a prerequisite for latency-sensitive strategies.

• Typical round-trip latency: sub-10 microseconds with colocation
• Speed bumps partially offset the advantage gained through colocation
• Remains essential infrastructure despite venue-level delays

The dispersion of trading activity across numerous lit exchanges, dark pools, and alternative trading venues. This fragmentation necessitates smart order routers to aggregate liquidity for complete execution.

• US equities trade across 16+ lit exchanges and 30+ ATSs
• Speed bumps create venue differentiation in a fragmented landscape
• Traders must weigh speed bump costs against liquidity access