When Balance-Sheet Costs Rise, Both Quotes Can Move Up

The corporate-bond market offers a useful diagnostic puzzle when the cost of dealer balance-sheet capacity rises: the economic cost of illiquidity can increase even if the headline bid-ask spread barely moves. This chapter isolates that capacity shock and follows its transmission from a dealer's carrying decision to inventory, customer access, bid and ask competition, and the liquidity yield spread. The point is not to assign one regulation a universal effect, but to understand why a muted spread response does not establish that intermediation became no more difficult.

The symptom: a quiet spread hides opposite-side repricing

A higher balance-sheet cost makes it less attractive for a dealer to carry a bond. In the model, that change is represented by lowering the dealer's convenience yield from holding the asset. The dealer's convenience yield is already net of the costs of using balance-sheet space, so the parameter is a compact way to represent a more expensive inventory position. It is not a direct measurement of any one capital or liquidity rule.

The first consequence is a lower equilibrium share of dealers holding the bond. The dealer sector carries less inventory because the return from being ready to sell to a customer buyer must now compensate for a larger carrying burden. That quantity response matters as much as the price response. If the model allowed only prices to adjust, it would miss the fact that the set of dealers positioned to serve each side also changes.

The second consequence runs in two directions. Fewer dealers hold inventory, so fewer dealers can respond when customers want to buy. Competition among ask-side dealers softens. A customer buyer therefore faces less pressure among dealers able to sell the bond, and the ask price rises relative to the competitive reference. In the model's terms, the ask spread widens for a given customer type, and ask-side profit increases.

At the same time, more dealers preserve balance-sheet space. More dealers are positioned to buy when customers want to sell. Competition on the bid side strengthens, so sellers can receive more competitive bids. The bid price rises toward the reference price and the bid spread narrows for a given seller. Bid-side profit falls because more capacity is competing for the same type of customer opportunity.

Those movements can make both customer-facing quotes rise. The ask rises because inventory-holding dealers face less competition. The bid rises because capacity-preserving dealers face more competition. Since the bid-ask spread is the difference between the two, the net change is not determined by the direction of either quote alone. The spread can remain almost unchanged, widen, or move slightly in the opposite direction depending on the relative strength of the two responses.

This is the hidden repricing behind the symptom. A report that says “the bid-ask spread did not increase” may be accurate and still incomplete. The market may have shifted from a state with more dealers carrying inventory to one with fewer inventory holders and more dealers waiting to buy. The two sides of customer service have been rebalanced even if their difference looks stable.

The electronic venue makes the inventory effect more visible. An electronic RFQ reaches multiple dealers, but a dealer without the bond cannot respond with a feasible ask to a customer buyer. When the inventory share falls, the probability that a queried dealer can sell falls as well, and the effective competition in the RFQ becomes thinner.