How do you earn $30 million in a month? For one anonymous tipster the answer did not involve winning the lottery, selling a football club or robbing a bank – last September, it involved spilling the beans to the US Securities and Exchange Commission and receiving the SEC’s highest-ever whistle-blower award in return.

It was a headline year for the SEC, which handed out nine awards of varying sizes to anonymous informants. The biggest award - the record-setting $30 million - was dished out to a non-US resident. Had they tipped off a UK regulator, their payout would be rather lower - nothing.