Linked Global Exchange
A satellite-linked scheme for trading commodities across time zones and exchanges as one continuous market — filed in 1984, when a 24-hour global market was still a proposal, not a fact of life.
International commodity trade exchange · — · filed 1984-10-05 · granted 1987-06-30 · expired 2004-10-05
Playable, self-contained demo. Nothing is sent anywhere; it runs entirely in your browser.
The story
US4677552 describes linking geographically separate commodity exchanges by satellite so trading could, in effect, follow the sun — one continuous market instead of a string of disconnected regional sessions. Filed October 5, 1984, it predates the always-on, follow-the-sun global markets that are now simply how trading works.
It expired on schedule in 2004. By then the idea it was reaching for — a market that never really closes — was infrastructure, not invention.
The demo below links three time-zone exchanges into one order book, the way the 1984 filing imagined it: trade any of them, watch the order flow the same book across the boundary.
Sources & further reading
Frequently asked questions
Can I use an expired or public-domain patent?
Once a patent's term ends or it lapses for non-payment, the invention it claimed generally enters the public domain and can be made, used, or sold without a license from the former owner. Separate copyrights, trademarks, or other patents may still apply to a specific product. This is general information, not legal advice.
Is an estimated date the same as a legal ruling?
No. Dates here are computed from public filing data and can differ from a patent's real status in either direction. Confirm against USPTO records before relying on one.
What does a maintenance-fee lapse mean?
US patents require maintenance fees at 3.5, 7.5, and 11.5 years after grant. If the owner stops paying, the patent lapses early and the invention enters the public domain years before its term would otherwise end.