Reserve Balances at Fed

What Is Liquidity?

Liquidity in financial markets refers to the ability to transact — to buy or sell an asset quickly, in size, without significantly moving its price. It is one of the most important and underappreciated forces in markets because liquidity appears abundant in calm markets and vanishes exactly when it is needed most.

Two Types of Liquidity

**Market liquidity**: How easily an asset can be traded. Measured by: - *Bid-ask spread*: The gap between buying and selling prices (tight = liquid) - *Market depth*: How much can be bought/sold before moving the price - *Volume and turnover*: How actively the asset trades

US Treasuries and S&P 500 futures are among the most liquid instruments in the world. Single stocks, small-cap bonds, and real assets are far less liquid.

**Funding liquidity**: How easily an entity can obtain cash or credit. A fund may hold liquid securities but face a funding liquidity crisis if its lenders withdraw credit lines. In 2008, many institutions held liquid assets but couldn't fund their balance sheets — the distinction proved fatal.

Why Liquidity Vanishes in Crises

Market makers — the dealers who provide liquidity by quoting bids and offers — withdraw in volatile markets because: 1. They face greater inventory risk holding positions they can't hedge 2. Their own funding liquidity dries up (they can't borrow to finance positions) 3. Regulatory capital constraints force balance sheet reduction

When dealers retreat, bid-ask spreads widen dramatically, markets become one-way (everyone wants to sell, nobody buys), and even normally liquid assets gap to distressed prices.

The Liquidity Spiral

Adrian and Shin described the "liquidity spiral": falling asset prices → mark-to-market losses → margin calls → forced selling → more price falls → further margin calls. Each step removes liquidity from markets, amplifying the spiral.

Global Dollar Liquidity

At the macro level, "global liquidity" refers to the availability of dollar funding globally. When the Fed is expanding its balance sheet, dollar liquidity is ample — risk assets globally benefit. When the Fed tightens, dollar liquidity shrinks — EM currencies weaken, credit spreads widen, and crypto sells off.

Key metrics: - **Fed balance sheet size**: Rising = more liquidity; falling (QT) = less - **DXY**: Dollar strength signals tightening global liquidity - **Cross-currency basis swaps**: Negative basis = dollar scarce internationally