Two Montgomery County businessmen have amassed enough wealth to lock in their place on this year’s Forbes World’s Billionaires List.

Bala Cynwyd’s Jeff Yass, cofounder of Susquehanna International Group, one of the largest and most successful trading firms on Wall Street, ranked at No. 156 with a net worth of $12 billion.

Last year, he was No. 184.

Yass became a pro gambler before starting trading on the Philadelphia Stock Exchange in 1981. He was backed by billionaire Israel Englander.

He cofounded Susquehanna in 1987 and helped grow it into a giant in options trading and making markets. The trading firm recruits and trains traders through poker tournaments, which are meant to sharpen their decision-making skills.

Bryn Mawr’s Michael Rubin, the founder and CEO of online sports merchandising retailer Fanatics, also made the list in No. 284 with a net worth of $8 billion. That is a significant jump compared with No. 859 last year.

Rubin dropped out of Villanova University to start GSI Commerce.

He sold his business to eBay in 2011 for $2.4 billion. As part of the deal, he acquired majority ownership of three assets eBay did not want, including Fanatics, Rue La La, and ShopRunner.

See the full Forbes World’s Billionaires List.