Given speculation that the US Federal Reserve will soon raise interest rates while the Iran turmoil continues to fan fears across asset classes, should investors boost cash holdings?

High cash allocations may feel safe, but an insidious risk lurks. Cash weighs on long-term returns, risking a brutal, underfunded long-term retirement – aged poverty. Few investors fully fathom this, to their peril.

Holding some cash, perhaps six to 12 months’ worth of expenses, is sensible – an emergency fund. It can improve investing performance by helping investors avoid forced securities sales at inopportune times. Or, if there is an upcoming major expense such as a home purchase, setting cash aside can be wise. Otherwise, investors should cap their cash.

Myriad studies show asset allocation (the mix of stocks, bonds, cash and other securities investors hold) determines most of one’s long-term returns. Market timing, stock picking and perceptions of “value” or “safety” pale in comparison. Asset allocation is the keystone choice investors make.

An investor’s goals, needs and time horizon (how long their assets must last to finance their goals) should largely determine allocation. Generally, the longer the time horizon and the more growth needed, the more a portfolio should be tilted towards higher-returning assets like stocks. Perhaps those who cannot stomach volatility should hold some bonds. But cash, in most cases, should be quite minimal.

Cash trap

Why? Cash delivers minimal returns. Consider US data in dollars for their global importance and long history. Since 1974, when gold standard controls ended, gold has delivered annualised 7.3 per cent returns through May. The US equities benchmark S&P 500, meanwhile, annualised 10.4 per cent returns since data start in 1925. Over the same stretch, 10-year US Treasury bonds annualised 4.7 per cent. US Treasury bills – a cash proxy – annualised lowest: 3.4 per cent. US inflation’s 3 per cent year-on-year average almost totally eroded cash returns. If an investor’s goals require any substantial growth, cash is highly unlikely to deliver it.

Similar trends hold since MSCI All-Country World Index (ACWI) data begin in 2000 (also in dollars). World stocks annualised 7.5 per cent while cash proxy Treasury bills annualised just 1.8 per cent – negative after adjusting for US inflation’s 2.6 per cent year-on-year average in that span.

Most investors do not know their asset allocation. To obtain it, consider asset classes – not accounts or “buckets”. First, total all accounts, including any brokerage account, savings or time deposits. Funds that blend stocks and bonds require closer inspection. For example, if an investor has $1 million in a fund that is 60 per cent stocks and 40 per cent bonds, they have allocated $600,000 to stocks and $400,000 to bonds.

Then subtract funds earmarked for known, near-term expenses or emergencies. Now divide each category – stocks, bonds, cash and other – by the total. These are the portfolio’s allocation percentages.

Conscious or not, allocations reveal an implied forecast. A high cash allocation equates to saying the lowest-returning asset class in modern history is more future-fit than historically higher-returning ones. Said otherwise, holding excess cash is implicitly bearish.