Just been scrolling through some wild stock performance data and honestly, some of the moves in the market over the past couple years have been absolutely insane. The S&P 500 is up around 60% in that stretch, which is already crushing its usual 10% annual average, but there are some individual names that have gone completely parabolic.

I stumbled across three that really stand out as top performers, and they're pretty interesting case studies for different reasons. Summit Therapeutics hit like 1,600% gains after their cancer drug ivonescimab showed better results than Merck's Keytruda in trials. That's the kind of move that gets everyone's attention, right? But here's the thing - the company has zero recurring revenue right now, which is a massive risk. The trial was in China too, so there's real uncertainty whether US regulators will even approve it. Feels like a wait-and-see situation to me.

Then there's Carvana, up around 1,330%. The used-car dealer's been on fire as interest rates stabilize and people get more optimistic about auto demand. Their financials actually improved too, which is why investors got excited. But margins are razor-thin, under 20%, and they posted a $72 million operating loss last year. Remember when this stock dropped 98% in 2022? That's the kind of volatility that keeps me up at night. You need consistency before going all-in on something like this.

Nvidia's the one that doesn't surprise anyone. Up 906%, and honestly it could've been higher given the AI boom. CEO Jensen Huang literally said demand for their Blackwell chips is insane - customers are waiting over a year just to get them. In their July quarter, sales jumped 122% year-over-year to $30 billion. That's the kind of growth story that keeps attracting capital.

What's interesting is looking at these three as part of a broader group of top 50 small cap stocks and growth plays that have really moved. Some of them have legitimate business fundamentals improving, while others are riding pure narrative. Summit and Carvana feel riskier to me - they've had massive runs and the downside could be brutal if sentiment shifts. Nvidia's valuation is already huge at nearly $3.5 trillion, so the returns might be more modest going forward, but the business momentum is undeniable.

The real question is whether you're buying these for the next leg up or if you're already late to the party. That depends a lot on your risk tolerance and how much you believe in each company's long-term story.