Shares of Gemini (GEMI) popped on their trading debut, then gave up ground.

The crypto exchange’s stock, which opened at $37—well above its $28 IPO price—closed Friday at $32, near its low of around $31 and off earlier highs around $46. Twin brothers Tyler and Cameron Winklevoss, the company’s founders, rang the opening bell at the Nasdaq in New York City Friday wearing t-shirts picturing a rocket in space.

Gemini, founded in 2014, set its IPO price overnight, arriving above an already-boosted expected range of $24 to $26. The company, officially known as Gemini Space Station, sold 15.1 million Class A shares, fewer than previously expected, but at a higher price. The deal raised $425 million, according to the company, which…