arbitrage
Concise Oxford English Dictionary © 2008 Oxford University Press:
arbitrage /ˈɑːbɪtrɪdʒ, ˌɑːbɪˈtrɑːʒ/
▶noun Economics the simultaneous buying and selling of assets in different markets or in derivative forms, taking advantage of the differing prices.
– derivatives
arbitrageur noun.
arbitrageur noun.
– origin ME, from Fr., from arbitrer ‘give judgement’.
'arbitrage' also found in these Oxford entries:

