Hedging A Market Maker's Book

Quote skewing — nudging prices to make an unwanted position less likely to grow — only works if the rest of the market cooperates by trading it back to flat. On a day where everyone wants to sell the same stock, a market maker's skewed bid can still get hit again and again, and the position keeps growing no matter how aggressively it's priced away. At some point the desk has to stop hoping the position trades itself flat and instead actively offload the risk somewhere else. That's hedging.

Hedging versus skewing

Skewing changes the price a market maker quotes in the same instrument to discourage further accumulation. Hedging takes on an offsetting position, often in a different but correlated instrument, to cancel out the risk of the position it already has — without needing anyone to trade against the original quote at all. A market maker long 50,000 shares of a stock can hedge by shorting the sector ETF, selling index futures, or buying puts, none of which require another counterparty to trade the original stock.

Worked example: hedging with an index future

A market maker ends up long 100,000 shares of a stock with a beta of 1.2 to the index, worth $5 million at the current price. Rather than carry that directional exposure overnight, the desk sells index futures with a notional exposure of $100{,}000 \times 1.2 \times \text{price}$, or roughly $6 million, sized so that a 1% move in the index — which the single stock is expected to roughly track, scaled by its beta — produces a futures gain that offsets the stock position's loss. The stock-specific risk (news about that one company) is not hedged this way; only the market-wide component is. If the whole market drops 2% and the stock drops with it, the futures hedge largely cancels that loss; if instead the stock alone drops on company news with the index flat, the hedge does nothing and the position loses money regardless — which is exactly why hedging is a risk-reduction tool, not a guarantee.

The cost side of hedging

Hedging isn't free: crossing the spread to sell futures, paying financing on a short position, or buying options all cost money, and a market maker's edge from spread capture is thin enough that over-hedging every small position can erase the profit the desk exists to earn. Desks typically hedge only once inventory crosses a threshold, or hedge a portion of the position rather than all of it, accepting some residual risk in exchange for lower hedging cost.