Remember 2019? That was genuinely a wild year for tech stocks. The whole market was up 30%, but the tech sector was absolutely crushing it at 48% for the year -- best performance in over a decade. People were talking about 5G networks everywhere back then, and honestly, it drove everything.

I was tracking which companies actually benefited most from all that hype, and the list was pretty interesting. Some of the winners you'd expect, others caught people off guard.

Say you were invested in Ultra Clean Holdings that year -- up 176%. This tech company makes semiconductor manufacturing equipment, so they rode the 5G wave hard. Most of their revenue came from two customers, Lam Research and Applied Materials, both of which were absolutely flying. When your main customers are up 115% and 86%, you tend to follow along.

Then there was Lattice Semiconductor, another 5G play up 178%. They make these FPGAs used in wireless infrastructure. As demand started ramping up, they hit record profitability. Communications and computing components were driving most of their revenue.

But not everything was about 5G infrastructure. Snap, the social media company, was up 191% that year -- surprising considering how much people had written them off. They stabilized their user base and figured out better monetization. Though the gains slowed in the second half when they gave cautious guidance.

Shopify was another monster performer at 195%. E-commerce was booming, and this tech company was providing all the tools merchants needed. They started moving into fulfillment too, acquiring warehouse solutions. Still losing money overall, but investors didn't care -- apparently some Silicon Valley companies were even interested in buying them.

Telaria, the ad tech specialist, hit 230%. They'd just posted their first quarter of positive EBITDA as connected TV advertising took off. Then they announced a merger with Rubicon Project to create this massive independent ad platform.

Sea Limited was up 247% -- a Southeast Asian gaming and e-commerce company licensing games from publishers like Tencent and Activision Blizzard. Free Fire had already grossed over a billion dollars since launch, and they were expecting Call of Duty: Mobile to keep the momentum going.

Digital Turbine jumped 304%. This tech company worked with wireless carriers to monetize mobile content through better ads. Heavy reliance on Verizon and AT&T, but they were looking to expand globally.

Diebold Nixdorf was up 340% -- mostly known for ATMs, but they had these kiosk systems helping retailers enhance in-store experiences. Dave & Busters was even installing their K-two systems.

Enphase Energy hit 466%. Solar microinverters -- benefited when Huawei exited the market, but honestly their products were already winning because they made installation simpler. They'd hit a million installed systems.

But the real story was Cardlytics at 500%. This credit card analytics tech company takes anonymized financial data and partners with marketers on rewards campaigns. Bank of America was their anchor, nearly 50% of revenue, but they'd just rolled out to Chase and were adding Wells Fargo. Seemed like they had way more runway ahead.

That whole 2019 run was something special. Tech was just dominating everything.