The emergence of the Omicron COVID variant has reignited volatility in the stock market. On the back of the uncertainty, investors may be wondering whether we could see another crash similar to that witnessed in March last year when the pandemic first spread across the world and prompted governments to shut down their economies.

Although now a distant memory, thanks largely to unprecedented government stimulus and monetary policy that fuelled a major rebound in stocks, looking back at the action from last year tumultuous period and the ensuing rally can offer some lessons for investors.

While the below stocks are in no way a reflection of the names that might prosper in the event of further market volatility this time around, nor are they a representation of the complete picture, here are some of the key takeaways that investors might be able to leverage to find other names with similar characteristics.

Stocks that defied the initial sell-off

One of the few ASX-listed names to post a convincing gain throughout the early stages of the pandemic, Fisher & Paykel Healthcare (ASX: FPH) jumped almost 50% between the end of January, 2020, and the start of July, 2020, with barely a pull-back of any sort. Although it has traded sideways ever since, the health care company pivot to respirators for the COVID crisis helped its share price rally, highlighting how adaptable businesses can find favour even in the midst of a market crash.Meanwhile, defensive retail names such as Coles (ASX: COL), Kroger (NYSE: KR) and Costco (NASDAQ: COST) were among those that shook off early cobwebs and performed robustly in comparison with the rest of the market in March, 2020, when selling was indiscriminate. These stocks demonstrated how day-to-day staple businesses can be defensive plays in times of uncertainty and panic, something also underscored by cleaning products firm Clorox (NYSE: CLX).Fortescue Metals Group (ASX: FMG), being one of the few names to trade ex dividend and still hold ground across the height of the COVID crash, showed that resources stocks are as much influenced by the commodity price cycle as the broader conditions in the stock market.And of course, as companies leveraged to the digitisation trend just started to turn things around, one of the earliest was Citrix Systems (NASDAQ: CTXS), a software firm tapping into the remote-work network theme. Those gains have now all been wiped out, but spotting an emerging trend as it unfolds can prove critical, as evidenced in the many other names from this sector that went on to sustain and build upon their rallies.

Top-performing stocks since the COVID bottom

Ecommerce became a big theme as lockdowns spread throughout the world last year, and the convenience of online shopping struck with consumers. Etsy (NASDAQ: ETSY), up 760%, and Wayfair (NYSE: W), up over 800%, were two of the biggest beneficiaries, and while the easy gains in these stocks may well be behind them, the lesson here was that companies which bring convenience into our day-to-day lives can see a paradigm shift in growth when the environment shifts with them.Unsurprisingly, vaccine makers have played a monumental role in helping gain some control over the pandemic, and they will soon be in attention again as they are tasked with the duty of assessing how their vaccines perform against the threat of the highly-mutated Omicron strain. Moderna (NASDAQ: MRNA) shares are up more than 1,200% since the end of February last year, while BioNTech (NASDAQ: BNTX) has gained around 900%.With its share price rising more than 1,200% from its COVID low, Tesla (NASDAQ: TSLA) is arguably the highest-profile turnaround following last year sell-off. The company underlying operations have improved markedly, aided by industry tailwinds as well. However, the takeaway here is that businesses with innovative prowess, let alone favoured by regulatory changes and ESG tailwinds, are well placed to attract investors. The above theme of course also turned into a boon for ASX battery metals names, with stocks like Pilbara Minerals (ASX: PLS), Vulcan Energy Resources (ASX: VUL), Lynas Rare Earths (ASX: LYC), Liontown Resources (ASX: LTR) and Novonix (ASX: NVX) all multiplying from their COVID lows.And finally, Square (NASDAQ: SQ), alongside its ASX acquisition in Afterpay (ASX: APT), will go down in the history books for their recoveries. As consumers turned to online shopping, and cash payments fell by the wayside, digital payments platforms became all the rage. While momentum may have since partially turned against these stocks, the lesson here is that tech platforms that underpin and facilitate changes in consumer behaviour have great growth potential when identified early on.