Despite mixed evidence, concerns about a decline of bond market liquidity persist. The typical worry is that a sudden decline in bond demand will cause prices to plunge and have serious knock-on effects.
Naturally, the issue merits attention: episodes in which market liquidity disappears rapidly can be disruptive (witness the flash crashes and flash rallies in various equity and bond markets in recent years). However, these incidents tend to be fleeting. Instead, from the perspective of financial stability, funding liquidity is the greater source of vulnerability...
Everyone seems to be worried about market liquidity – the ability to buy or sell a large quantity of an asset with little or no price impact. Some observers complain that post-crisis financial regulation has reduced market liquidity by forcing traditional market makers – say, in corporate bonds – to withdraw. Others focus on episodes of sudden, unforeseen loss of liquidity – for example, in the equity and Treasury markets – suggesting that structural changes (such as the spread of high-frequency algorithmic trading) are now a source of fragility. We’ve written about these issues before (here and here).
But it is worth taking a step back to ask exactly what it is that we care about. The answer turns out to be complex, so working out remedies will be a big challenge...
