Tuesday was a breakout day for the market, as major stock indexes climbed higher to approach record levels on hopes that the U.S. and China will be able to resolve their trade differences at the coming G-20 meeting. With signs that the global economy is slowing, investors have increasingly believed that a shift in monetary policy will be necessary in order to sustain growth, and they'll get their first hint later this week at whether the Fed will live up to their expectations. Meanwhile, with most stocks sharply higher, a few stood out as particularly big winners. SunPower (SPWR -55.01%), Snap (SNAP -1.17%), and G1 Therapeutics (GTHX -0.28%) were among the top performers. Here's why they did so well.

The clouds part for SunPower

Shares of SunPower soared nearly 23% following favorable comments from analysts at Goldman Sachs. Goldman boosted its rating on the solar power specialist from neutral to buy and increased its price target by more than 80% to $11 per share. SunPower is in a better position than many of its rivals to avoid the negative impact of tariffs, because it has acquired substantial manufacturing capacity within the U.S. and has also gotten exemptions on some of the materials it imports. With California requiring residential solar on new construction beginning in 2020, SunPower can expect another jump in demand that could help produce longer-term growth well into the future.

Rows of solar panels on a roof, with view of skyline behind.

Image source: SunPower.

Snap gets some love

Snap saw its stock climb almost 10% as the social media company kept gathering praise from Wall Street analysts. The latest moves came from BTIG, which increased its price target by 33% to $20 per share. BTIG sees the company's flagship Snapchat platform as recovering more quickly than most investors are giving it credit for, and a combination of better premium content, stronger advertising, and features that keeping users engaged could sustain growth for the foreseeable future. Unfortunately for long-term investors, even a move toward $20 per share would still leave the stock with losses since its 2017 IPO, but Snap's gains since late last year are impressive.

G1 scores a win

Finally, shares of G1 Therapeutics jumped 24%. The clinical-stage oncology specialist said that a phase 2 trial of its trilaciclib treatment for metastatic triple-negative breast cancer produced encouraging data. The trial's results on overall survival showed that women suffering from the disease lived significantly longer when using trilaciclib compared to just getting traditional chemotherapy. CEO Mark Velleca noted that "triple-negative breast cancer is the most aggressive type of breast cancer, and women diagnosed with metastatic TNBC need new treatment options." G1 hopes to provide that option as trials progress, and investors hope that the company will keep getting favorable results in those trials.