Capitolis' new idea resembles an old one: Banks have long sliced up and sold their big corporate loans to other banks and investors. Capitolis figured out how to use this syndication concept to turn all kinds of banking products—foreign-exchange swaps and lines of credit, to name a few—into a kind of fixed-income security or loan they can sell to investors.
Capitolis’s plan to outsource banks’ capital needs, while still in its infancy, has the potential to reshape their role in the market and the broader economy. Divorcing the capital required for transactions from the process of executing them could allow banks to serve more customers—businesses and consumers alike—without taking on so much risk that they could blow up the financial system. The goal, the company’s founders say, is a market better able to absorb big spikes in trading volume and loan demand. “When it’s all over, we will have uncoupled capital from the underwriting equation,” said Mr. Mandelzis. “We’re going to look back and wonder how they used to do it when it was bundled.”