A couple of miles from Wall Street, on the Western bank of the Hudson River, sits a vault in Jersey City maintained by the Depository Trust & Clearing Company. You might never have heard of the DTCC, but if you own stock, bonds or a mutual fund, it takes care of something that belongs to you.

The DTCC is the clearinghouse for U.S. capital markets. Its Jersey City vault contains about a million physical stock and bond certificates, representing some undisclosed portion of the $43 trillion in total assets the organization holds in custody. This is the center of the entire American stock-trading system. Each share has an owner, and – no matter how fast it changes hands – a clearinghouse keeps track of who owns what.

This year, Patrick Byrne, the CEO of Overstock.com and would-be financial revolutionary, is taking the first steps in a campaign to smash open the vault. Or, really, to eliminate it - and with it, the whole system that makes the vault necessary. On April 1, the Securities and Exchange Commission approved a request by a private stock exchange partnered with Overstock to deal in "digital securities."