Evan Spiegel was already a very rich man. But by the end of the day today, he'll be an even richer man.

Snap, Inc. — the company behind Snapchat — started trading Thursday morning in its initial public offering at the New York Stock Exchange. Going public means that $SNAP can start publicly trading as a stock, meaning you can go buy some right now. Before, the company was privately held, meaning there was no public market to buy and sell Snap shares.

Snap shares jumped almost immediately after they started trading, adding 50 percent (as of mid-afternoon in New York). That means Spiegel's stake in Snapchat increased in value by a cool $1.5 billion, according to Bloomberg.

Spiegel owns 21.8 percent of class A common stock in the "camera company," as he likes to call it.

Tweet may have been deleted

With the $17 stock price, Snap is valued at $24 billion. The company aimed to raise $3 billion in capital through the IPO.

Along with all his money, Spiegel and his co-founder will maintain control of the company. Spiegel's 21.8 percent of stock along with co-founder Bobby Murphy's 21.8 percent stake ensure that the two founders will still control Snap even once investors buy large stakes in the company, thanks in part to the company's structure that gives different types of stock different voting power.

Spiegel, 26, made $2.4 million as CEO in 2016, but has said he will reduce his annual salary to $1 now that he's a billionaire.

All of this is pretty similar to one other IPO: Facebook's. In 2012, Mark Zuckerberg became an instant billionaire 19 times over when Facebook went public (even if that IPO didn't go as planned). Zuckerberg also cut his salary to $1.

It's worth noting that other tech companies experience big days when they first started trading. Snapchat's big increase doesn't necessarily mean they'll do well in the future.

Tweet may have been deleted

Snap's IPO is the biggest tech IPO on Wall Street since then.