LMAX's "Disruptor" concurrent-server pattern, claiming to be a higher-throughput, lower-latency, and lock-free alternative to the SEDA pattern using a massive ring buffer. Good discussion here at SO. (via Filippo)

'The two men worked out how the computerized system would react to certain trading patterns – allowing them to influence the price of low-volume stocks.' Yet another risk of automated traders

'as the computers of the high-frequency traders traded contracts back and forth, a “hot potato” effect was created, the report said, as contracts changed hands 27,000 times in 14 seconds, but with eventually only 200 actually being bought or sold.' upshot: horrifically complex distributed feedback loops now directly impact our economies -- great :(