■ U.S. stocks went on another dizzying ride Friday and worked their way back from an early-morning plunge to send the Standard & Poor’s 500 index to its first gain in four days.

Dow roars back, all but erases drop that neared 400 points.

U.S. stocks ended a volatile session higher, paring a weekly decline, as investors speculated that President Donald Trump’s tough tariff talk won’t translate into the most severe protectionist policies. Treasuries slumped with the dollar.

The S&P 500 Index staged a late-day rally to finish near its high for the session. The gain trimmed its weekly decline to 2 percent. The Dow Jones Industrial Average roared back to all but erase a drop that approached 400 points at its worst.

The threat of a trade war sparked the early selling, only to ease as the president’s recent history of backing off seemingly iron-clad policy positions gave rise to speculation the actual levies may not disrupt global growth.

“People always forget that Trump is a negotiator, and when you negotiate, you don’t negotiate from the point where you want it to end up — you put an anchor out, and you negotiate from that anchor,” said Brent Schutte, chief investment strategist of Northwestern Mutual Life Insurance Co.’s wealth-management unit. “Yesterday was an anchor. I do believe there will be some give back if others are willing to give the U.S. something.”

Earlier, Trump pushed back against a wave of criticism of the steel and aluminum tariffs he proposed Thursday, saying “trade wars are good.” The possibility of the levies raised the prospect of tit-for-tat curbs on American exports and higher prices for domestic users, further clouding the outlook for economic growth at a time when central banks around the world are embarking on policy-tightening or approaching it.

“When people are nervous, they’re more likely to react and overreact more strongly,” said James Norman, head of equity strategy at QS Investors. “And that’s the kind of market environment we’re in right now.”

Elsewhere, the Stoxx Europe 600 Index sank more than 2 percent for a fourth day of losses, while Germany’s DAX Index reached its lowest level since August. Japan led the retreat in Asia earlier, with the Topix Index tumbling after Bank of Japan Governor Haruhiko Kuroda mentioned for the first time a possible time frame for discussing an exit from its extraordinary easing program. The yen surged to the strongest since 2016 and shares from Hong Kong to Australia declined.

Kuroda’s comments were seen as further evidence the era of massive stimulus that boosted asset prices and slashed borrowing costs is coming to an end.