The Financial Post reports in its Thursday edition that the world's central bankers have vowed in unison to keep interest rates higher for longer if necessary to tame inflation, and that in turn fuelled a $5.5-trillion (U.S.) stock sell-off on Wall Street. A Bloomberg dispatch to the Post says that after rallying on bets that the U.S. Federal Reserve is on the cusp of easing policy, a slew of interest-rate-sensitive investing strategies are taking a beating this August. Blame benign economic data that suggest the age of elevated borrowing costs and rich valuations across risky assets will endure after a stunning first-half rally. From buying meme stocks and dumping the dollar to betting against swings in stock prices, many popular trades have become losers. The backdrop for the global market tumult is higher yields at precisely the wrong time. One estimate pegs the U.S. growth rate at an astonishing 5.9 per cent, and longer-maturity bonds have been hit particularly hard. Those securities have lost 4 per cent so far this month as of Aug. 28, putting them on track for a 3-per-cent plunge for the year. Bank of America, Goldman Sachs and TD Securities have abandoned their dip-buying call as market losses deepened.