What looming tech bust? Successful debuts of two richly valued tech start-ups have silenced talk of a tech crash — for now.

Mobile payments processor Square (SQ) and online dating conglomerate Match Group (MTCH) saw their shares jump 45% and 23%, respectively Thursday on their first day of trading. The moves awarded these companies a combined market value of $7.7 billion – underscoring investors’ hunger for a piece of young firms poised to capitalize on the mobile revolution.

Seeing the strong first-day debut of these stocks comes as a big relief to investors who feared the days of huge valuations for tech companies might be drawing to a close as markets get more skeptical. A number of young companies with promising apps have won massive valuations on private markets, which some thought was unrealistic and due to get a reality check by the more discerning public stock market.

Yet Square and Match passed the tests of market appetite for companies nicknamed “unicorns” in Silicon Valley for being rare and prized tech start-ups valued at $1 billion or more. Following the day’s trading, Square is worth $4.2 billion at Thursday’s closing price of $13.07 and Match is valued at $3.5 billion based on its closing price of $14.74. The tech titans building these companies are certainly profiting big-time. Square co-founder Jack Dorsey pocketed another $283 million on the company as he’s the largest single shareholder and didn’t sell in the initial public offering. That puts him squarely in the billionaire’s club if you add his stake in micro blogging site, Twitter (TWTR).

Square and Match are just a microcosm of the huge valuations being given to tech titans who are dominating online business. Online retailer Amazon (AMZN), for instance has seen its shares more than double this year and are trading for 944 times their profit over the past 12 months.

Despite the strong debuts of these Square and Match, though, investors have lingering worries. Part of Square’s strong-first day debut was the result of the shares being sold at a deep discount to initial investors. Big mutual funds and other privileged investors were offered shares at the initial price of $9 a share, down from the $11 to $13 range initially expected. That deep price cut made a first day pop much more likely.

Meanwhile other members of a new crop of tech darlings have already crashed and burned from their IPOs. Sports camera maker, GoPro (GPRO), for instance, is now trading 17% below its initial price set in mid-2014 and is down 75% over the past 12 months. All told, 57% of the 163 companies to sell stock for the first time this year are trading below their initial offering prices, says Renaissance Capital.

GoPro is the rule in tech IPOs — not the exception. The 22 technology IPOs of the year are now up just 0.6% from their offering prices, says Renaissance, which manages IPO-focused exchange-traded funds. That means the giddy investors who pushed these deals up 17.9% on average on their first days of trading are down big.

But forget about reality for now. Investors who want to believe in unicorns just got a glimpse of two of them.

Follow Matt Krantz on Twitter @mattkrantz

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