The Financial Post reports in its Friday edition that in a few short weeks, U.S. President Donald Trump has started silencing the buy-the-dip traders who set the tone on Wall Street for the better part of two decades. A Bloomberg dispatch to the Post says that in their place are growing calls to lock in profits and sit on the sidelines while Mr. Trump's trade-war chaos casts uncertainty over who, if anyone, will emerge as the new era's stock-market winners. "Buying the dip now is like buying discounted tickets to a show without knowing who's performing," said Dave Mazza at Roundhill Investments. "Unlike the recent path when buying every dip was reliable, the heightened uncertainty of tariffs and trade policy means investors could end up with either a blockbuster or a flop." Mr. Trump's style -- a scattershot approach resulting in a dizzying cycle of tariffs that are on, off and on again -- has shattered confidence that any bounceback will stick. However, data from Bank of America show that clients bought stocks for a sixth straight week through last week. The so-called fear gauge -- the Cboe Volatility Index -- shows volatility is increasing but not at red-flag levels. It is capital preservation time.