Liquidity risk

Culp defines the liquidity gap as the net liquid assets of a firm. The excess value of the firm's liquid assets over its volatile liabilities. A company with a negative liquidity gap should focus on their cash balances and possible unexpected changes in their values.

As a static measure of liquidity risk it gives no indication of how the gap would change with an increase in the firm's marginal funding cost.

Culp denotes the change of net of assets over funded liabilities that occurs when the liquidity premium on the bank's marginal funding cost rises by a small amount as the liquidity risk elasticity. For banks this would be measured as a spread over libor, for nonfinancials the LRE would be measured as a spread over commercial paper rates.

Problems with the use of liquidity risk elasticity are that it assumes parallel changes in funding spread across all maturities and that it is only accurate for small changes in funding spreads.

The bid–ask spread is used by market participants as an asset liquidity measure. To compare different products the ratio of the spread to the product's bid price can be used. The smaller the ratio the more liquid the asset is.

This spread is composed of operational, administrative, and processing costs as well as the compensation required for the possibility of trading with a more informed trader.

Hachmeister refers to market depth as the amount of an asset that can be bought and sold at various bid–ask spreads. Slippage is related to the concept of market depth. Knight and Satchell mention a flow trader needs to consider the effect of executing a large order on the market and to adjust the bid–ask spread accordingly. They calculate the liquidity cost as the difference of the execution price and the initial execution price.

Immediacy refers to the time needed to successfully trade a certain amount of an asset at a prescribed cost.

Hachmeister identifies the fourth dimension of liquidity as the speed with which prices return to former levels after a large transaction. Unlike the other measures, resilience can only be determined over a period of time, i.e., resilience is the capacity to recover.

Liquidity-adjusted VAR incorporates exogenous liquidity risk into Value at Risk. It can be defined at VAR + ELC (Exogenous Liquidity Cost). The ELC is the worst expected half-spread at a particular confidence level.[6]

Another adjustment, introduced in the 1970s with a regulatory precursor to today's VAR measures,[7] is to consider VAR over the period of time needed to liquidate the portfolio. VAR can be calculated over this time period. The BIS mentions "... a number of institutions are exploring the use of liquidity adjusted-VAR, in which the holding periods in the risk assessment are adjusted by the length of time required to unwind positions."[8]

Alan Greenspan (1999) discusses management of foreign exchange reserves and suggested a measure called liquidity at risk. A country's liquidity position under a range of possible outcomes for relevant financial variables (exchange rates, commodity prices, credit spreads, etc.) is considered. It might be possible to express a standard in terms of the probabilities of different outcomes. For example, an acceptable debt structure could have an average maturity—averaged over estimated distributions for relevant financial variables—in excess of a certain limit. In addition, countries could be expected to hold sufficient liquid reserves to ensure that they could avoid new borrowing for one year with a certain ex ante probability, such as 95 percent of the time.[9]

The FDIC discuss liquidity risk management and write "Contingency funding plans should incorporate events that could rapidly affect an institution’s liquidity, including a sudden inability to securitize assets, tightening of collateral requirements or other restrictive terms associated with secured borrowings, or the loss of a large depositor or counterparty."[10] Greenspan's liquidity at risk concept is an example of scenario based liquidity risk management.

If several liquidity providers are on call then if any of those providers increases its costs of supplying liquidity, the impact of this is reduced. The American Academy of Actuaries wrote "While a company is in good financial shape, it may wish to establish durable, ever-green (i.e., always available) liquidity lines of credit. The credit issuer should have an appropriately high credit rating to increase the chances that the resources will be there when needed."[11]

Bhaduri, Meissner and Youn discuss five derivatives created specifically for hedging liquidity risk.:

• Withdrawal option: a put of the illiquid underlying at the market price.
• Bermudan-style return put option: right to put the option at a specified strike.
• Return swap: swap the underlying's return for LIBOR paid periodically.
• Return swaption: option to enter into the return swap.
• Liquidity option: "knock-in" barrier option, where the barrier is a liquidity metric.

Amaranth Advisors lost roughly $6bn in the natural gas futures market in September 2006. Amaranth had taken a concentrated, leveraged, and undiversified position in its natural gas strategy. Amaranth's positions were staggeringly large, representing around 10% of the global market in natural gas futures.[12] Chincarini notes that firms need to manage liquidity risk explicitly. The inability to sell a futures contract at or near the latest quoted price is related to one's concentration in the security. In Amaranth's case, the concentration was far too high and there were no natural counterparties when they needed to unwind the positions.[13] Chincarini (2006) argues that part of the loss Amaranth incurred was due to asset illiquidity. Regression analysis on the 3 week return on natural gas future contracts from August 31, 2006 to September 21, 2006 against the excess open interest suggested that contracts whose open interest was much higher on August 31, 2006 than the historical normalized value, experienced larger negative returns.[14]

Northern Rock suffered from funding liquidity risk in September 2007 following the subprime crisis. The firm suffered from liquidity issues despite being solvent at the time, because maturing loans and deposits could not be renewed in the short-term money markets.[15] In response, the FSA now places greater supervisory focus on liquidity risk especially with regard to "high-impact retail firms".[16]

Long-Term Capital Management (LTCM) was bailed out by a consortium of 14 banks in 1998 after being caught in a cash-flow crisis when economic shocks resulted in excessive mark-to-market losses and margin calls. The fund suffered from a combination of funding and asset liquidity issues. The asset liquidity issue arose from LTCM's failure to account for liquidity becoming more valuable, as it did following the crisis. Since much of its balance sheet was exposed to liquidity risk premium, its short positions would increase in price relative to its long positions. This was essentially a massive, unhedged exposure to a single risk factor.[17] LTCM had been aware of funding liquidity risk. Indeed, they estimated that in times of severe stress, cuts on AAA-rated commercial mortgages would increase from 2% to 10%, and similarly for other securities. In response to this, LTCM had negotiated long-term financing with margins fixed for several weeks on many of their collateralized loans. Due to an escalating liquidity spiral, LTCM could ultimately not fund its positions in spite of its numerous measures to control funding risk.[1]