Somewhat dependent on product and country. Generally in the US we have monopoly clearing and they clear down to the firm level. So the clearing house doesn't know who you are - just your firm. Go to Asia and Australia and the ASX - for example - clears down to the customer so they know who you are. There is also some common clearing in Asia. OCC in the United States clears down to firm and that makes the product fungible - with the exception of a few monopoly options. So you can open an order for Apple options on an exchange and close the trade on another exchange because of central clearing. Again depending on market and country clearing can be fairly quick or end of trading session. The huge benefit of clearing down to the customer is the ability to market directly. The firm still guarantees the trade to the clearing house. So it's very dependent on the product and country. Trade the smaller exchanges in the EU and you have some real efficiency issues - most likely why Eurex is so popular. In the U.S. futures and futures options aren't fungible - securities options are, again with exception of monopoly product. SPX options only trade one exchange - SPY options trade on all exchanges. Stocks are pretty simple unless you go cross border. I can buy IBM on the IEX and sell it on the NYSE - no problem. If I buy IBM in London at night and trade out of it during the day on the NYSE - depending on my broker - it can be really easy or a mess.