The plumber who became the rails
There is a version of this story where Yoshi Yokokawa is a quant at a hedge fund, running neural networks against price feeds, doing well enough. That version ended around 2017, when he realized the brokerage infrastructure under every trading system was a mess of legacy APIs, compliance friction, and gatekept access. The frustration of having no clean entry point became the founding insight of Alpaca.
Yoshi grew up in Japan. As a teenager, he was packaging CD-ROMs for SoftBank under Masayoshi Son - long before SoftBank became a global venture empire. That early encounter with scale-minded entrepreneurship stuck. After studying at Keio University and later at Boston University with a focus on finance, he landed at Lehman Brothers in 2005, working in fixed income capital markets on securitization and structured products. He was there in 2008 when it all collapsed.
Watching Lehman fall from the inside gave Yoshi something most fintech founders lack: a visceral understanding of what happens when financial infrastructure fails. He went on to Nomura as a forex trader and later VP of Structured Finance. Then, in 2013, he pivoted entirely - cofounding Ikkyo Technology, a computer vision company that would eventually be acquired by Kyocera Communication Systems. First exit. Not last.
"I think gut is actually the output of data, in my opinion, but in a very unconscious way."- Yoshi Yokokawa
In 2017, Yoshi cofounded Alpaca with Hitoshi Harada and Yuki Hayashi. The original vision was building deep neural net models for trading funds. The execution revealed the actual problem: there was no developer-friendly brokerage API. Stripe had done it for payments. Plaid had done it for banking. Nobody had done it for trading. Alpaca became that answer.
Y Combinator's Winter 2019 cohort validated the direction. What followed was systematic. Commission-free stock trading for developers. Fractional shares. Options. Crypto. And crucially: the infrastructure layer that lets other fintechs embed trading into their own products - without needing a broker-dealer license, a compliance team, or 18 months of regulatory runway.
By 2026, Alpaca's Broker API powers over 300 fintech partners across 45 countries. The $150 million Series D in January 2026 - led by Drive Capital with Citadel Securities, BNP Paribas, MUFG Innovation Partners, Kraken, and DRW Venture Capital at the table - brought total funding to nearly $289 million at a $1.15 billion valuation. API usage grew nearly 4x quarter-over-quarter in Q1 2026 alone, a signal that AI agents are beginning to trade at scale through Alpaca's infrastructure.
Yoshi calls the end goal a "Global Financial OS" - not a product, but an operating system for the financial world. Windows for trading. Android for investing. The analogy is deliberate. He isn't building the apps. He's building the platform everything else runs on.
