Stocks could be primed for large gains. The S & P 500 has soared more than 18% since hitting a closing low on April 8. That marks only the fifth time since 1970 that the broad market index has surged that much over just 25 trading days. The latest move higher comes as global trade tensions ease, with the U.S. temporarily pausing or cutting steep tariffs on imported goods. This week, China and the U.S. agreed to lower levies for 90 days as both countries work to hammer out a broader trade agreement. If history is any guide, stocks should now see sizable gains over the coming year. The S & P 500 on average has risen about 30% in the 250 trading days that followed such a strong 25-trading-day run. That includes two instances when the benchmark popped more than 40%. Week to date, the S & P 500 and Nasdaq Composite are up 4% and 6.8%, respectively. The Dow Jones Industrial Average has also advanced nearly 2%. This week's rally puts the S & P 500 just 4.2% below its February all-time high. "What a switch, even for this market," wrote Tom Essaye of The Sevens Report. "A month ago (and even much later than that) the outlook for the economy was stagflation and the outlook for stocks was bordering on a 'lost decade' similar to what was witnessed in the 1970s and 2001-2009. But, oh how things have changed." But Essaye urged clients to stay cautious. "There is a lot of uncertainty to dismiss."