The first half of 2020 was a wild ride for investors, between a (short-lived) bear market and an ensuing record-setting recovery, with unprecedented volatility in between.

Through the mid-year point, results for the biggest U.S. indexes were an equally wild mix. Amid the coronavirus carnage in the markets, the Dow Jones Industrial Average fell 9.6% and the S&P 500 declined 4%. On the other hand, the tech-heavy Nasdaq rose 12.1%. Gold did even better, up 17.4%.

But those gains are nothing compared to the best performers on the stock market, where the top ten S&P 500 stocks eclipsed those numbers, and the best Nasdaq stocks went even further—with returns that more than doubled their value, at a minimum.

Perhaps surprisingly, several pandemic darling stocks such as Netflix, whose subscribers surged with people stuck at home, didn't even crack the top 10—even though Netflix stock returned nearly 41% in the first half of 2020.

In the S&P 500, the first half's best performing stocks included Clorox (up nearly 45% as its sanitizing wipes sold out everywhere) and Amazon (rising more than 49% as people relied more on e-commerce), as well as electronic payments company PayPal (up 61%) and semiconductor giant Nvidia (up almost 62%).

In an even bigger surprise, the two biggest winners in the S&P 500 were both health care stocks—though their performance can't entirely be credited to a coronavirus boost. The best-performing S&P 500 stock was DexCom, a maker of smart glucose monitors for diabetes patients, which rose more than 85%, followed by Regeneron (up 66%), which is trying to replicate its success with Ebola treatments in finding an antidote for COVID-19.

Those returns, however, were all overshadowed by the best performers in the Nasdaq. (For this article, we looked only at companies with at least $10 billion in market value). While Tesla came in at No. 5, with a first-half return of over 158%, that performance was dwarfed by its upstart competitor, Nikola, which came in first, soaring 554%. Nikola has had an eventful year; it just began taking pre-orders for its new electric pickup truck, and its share price soared after it joined the Nasdaq in June via a reverse merger.

Coming in second among Nasdaq stocks, of course, was Zoom Video—the virtual meeting software company that has been the talk of the pandemic among corporate employees and home fitness enthusiasts alike, rising nearly 273%.

Even strong contenders like Peloton Interactive, whose stock more than doubled in value as its at-home bikes and workout classes were a quarantine hit, didn't quite make the list.

On the flip side, a good many other stocks—as might be expected— have had a terrible 2020 so far. The worst performers among the S&P 500 include the major cruise lines like Norwegian (down 72%) and Carnival (down nearly 68%), along with a smattering of energy companies and airlines.

One noteworthy anomaly among the losers is beauty company Coty. That stock fell more than 60% in the first half of the year—and that's even after Coty stock surged this week on news that it would take a 20% stake in Kim Kardashian's cosmetics brand.