It wasn't just Evan Spiegel who got rich in Snap Inc.'s IPO yesterday.

A California high school has made millions of dollars from the initial public offering of shares in Snap Inc.018 Archives the company behind Snapchat.

The board of the Saint Francis high school in Mountain View agreed to invest $15,000 in seed money in Snap in 2012, when the company was just getting started.

They had been invited to do so by one of the student's parents, a venture capital investor with Lightspeed Venture Partners, the high school president said in a letter issued to the school community Thursday.

"We didn't have real high expectations," the school's former president, Kevin Makley, told CNNTech. "We collectively decided that this was going to be a ... small investment. So we'll take a shot at it."

The school held onto the investment until this week, when Snap shares sold for $17 each in an IPO. The share price rocketed another 44 percent higher when trading began Thursday.

The school was quoted by media as saying they sold two-thirds of their shares at $17 each, to raise $24 million. The school will use the money for its strategic plan to recruit faculty and "make Catholic education more affordable and accessible."

"The school's investment in Snap - which this morning announced the completion of its IPO - has matured and given us a significant boost," said the high school president, Simon Chiu, in the letter.

The Associated Press contributed reporting.