Washington Busmess JULY *9, 1982  
NEW YORKÛÓMost investors failed to keep up with inflation during the turbulent 1970s. But the closest thing to a break-even investment was also the simplest and safest: 90-day U.S. Treasury bills, or their attractive surrogates, money-market mutual funds.</br></br>Both in 1981 and over the past decade, Treasury bills provided better overall investment returns than stocks and bonds, according to a recent study by the accounting firm of Peat Marwick Mitchell and Co.</br></br>Stocks or bonds did manage to outperform Treasuries for short periods during the 1970s. The American Stock Exchange index bounded ahead over the entire 10-year period (but to get the same return in your own portfolio you had to be heavily invested in ASE energy stocks). You might also have done well in gold and other exotics, if you bought and sold at exactly the right time.</br></br>But most investors donÛªt run in and out of markets, and rarely buy at exactly the right time. They invest for their own longterm future in reasonably secure investments that they hope will grow.</br></br>Long-term investors did well with stocks and mutual funds (but not bonds) during the 1950s and most of the 1960s. But in the 1970s, Treasury bills were the answer. T-bills are continuing their excellent performance into the 1980s.