The Investor's Diving Board Dilemma

To jump or to tiptoe, that is the question.

In a recent piece for the New York Times, Jeff Sommer looks at the issue of whether investors looking to deploy a large chunk of capital in the market are better off doing it all at once or bit by bit.

“Bernstein Global Research recently conducted its own study of the subject, and was able to quantify some of the cost of investing gradually,” Sommer writes. “Using the Standard & Poor’s 500-stock index and its predecessors, Bernstein examined the rolling one-year returns of the stock market through 12-month periods from the beginning of 1926 to the end of 2013 — a total of more than 1,000 such periods. It compared lump-sum investments made at the beginning of each period with stock purchases made through ‘dollar-cost averaging’ — regular monthly investments in the S.&P. 500 for 12 months. Money on the sidelines stayed in three-month Treasury bills.”

The results: The average one-year return was 12.2 percent for immediate investments into stocks, 8.1 percent for the dollar-cost-averaging portfolios, and 3.6 percent for the cash holdings.

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Sommer also looks at how the worst-case timing scenarios would have played out in the period Bernstein examined — and he says immediate investors who entered the market at terrible times would’ve made their money back surprisingly quickly. “For example, the worst 12-month period since 1926 began on July 1, 1931, during the Depression: The stock index lost 67.6 percent, including dividends, in those 12 months,” he writes. “Yet it would have taken only 39 months — 3.25 years — to erase all your losses, assuming that you had stayed in the market.”

Starting on March 1, 2008, meanwhile, the market lost 43.3 percent over the next year. “Many people bailed out of stocks then and never went back,” Sommer notes. “But if you had stayed fully invested in the market, you would have recovered all of your losses within 22 months — and would be sitting on enormous gains today.”

But sitting tight through the huge declines is, of course, the hard part. Writes Sommer: “As [Bernstein Global Wealth Management’s Seth] Masters says, ‘Achieving a level of emotional comfort may be the most difficult part of investing.’ Whatever the numbers show, that helps to explain the enduring appeal of tiptoeing into the market.”