What Black Monday says about a flash crash

It took the whole of Black Monday for the Dow to fall 23 per cent, as brokers on the floor of the New York Stock Exchange looked in vain for buyers at lower and lower prices. In today's high-speed world, crashes can come and go in moments, and trading firms can be taken to the brink of collapse by an errant piece of computer code. The FT's Stephen Foley speaks with Icap managing director Kenny Polcari, Getco chief technology officer Jon Ross and Canadian regulator Susan Wolburgh about how such events are influencing the marketplace.