What patents reveal, once they stop mattering legally
A patent record is a timestamp with a business story attached: what a company bet on, when they stopped paying to protect it, and what that timing says in hindsight.
US11170444
The New York Stock Exchange itself filed a trade-quality-indication patent in 2021 — and let it lapse for nonpayment four years later, with fifteen years of possible term still ahead of it.
US8285619
Filed in the bag-of-words era of natural language processing, this patent expired on its own timeline right before large language models made 'read the news, trade the sentiment' a mainstream idea.
US3946218
The oldest grave in the corpus: a Hewlett-Packard calculator patent from 1974, for a machine that could compute a bond's yield to maturity at the push of a button — a genuinely novel thing to put in someone's hands, fifty years ago.
US4346442 & US4376978
Merrill Lynch's Cash Management Account — the product that first swept brokerage cash into money-market funds and let you write checks against your portfolio — patented twice, three months apart, in 1980.
The 10 oldest graves in the corpus
By grant date. The bottom of the timeline — yield-to-maturity on a calculator, before there was an internet to check it against.
| Patent | Title | Assignee | Granted | Term end (est.) |
|---|---|---|---|---|
| US3946218 | General purpose calculator with capability for performing yi | Hewlett-Packard Company, L.P. | 1976-03-23 | 1994-10-10 |
| US4334270 | Securities valuation system | — | 1982-06-08 | 1999-06-08 |
| US4346442 | Securities brokerage-cash management system | Merrill, Lynch, Pierce, Fenner & Smith | 1982-08-24 | 2000-07-29 |
| US4376978 | Securities brokerage-cash management system | Merrill, Lynch, Pierce, Fenner & Smith | 1983-03-15 | 2000-10-22 |
| US4412287 | Automated stock exchange | — | 1983-10-25 | 2002-09-15 |
| US4473824 | Price quotation system | Nelson B. Hunter | 1984-09-25 | 2003-07-22 |
| US4486853 | Apparatus for receiving and displaying continuously updated | Telemet American, Inc. | 1984-12-04 | 2001-12-04 |
| US4525779 | Conversational video system | Reuters Limited | 1985-06-25 | 2003-03-30 |
| US4532509 | Communication system having timer controlled field stations | Federal Signal Corporation | 1985-07-30 | 2002-07-30 |
| US4566066 | Securities valuation system | — | 1986-01-21 | 2003-01-21 |