Bookmakers in the UK are likely sleeping easier this weekend after the Conservative party won an outright majority in Thursday’s General Election.

Prime Minister David Cameron’s Tories won 331 seats in the 650-seat House of Commons, a net gain of 25 seats. Ed Milliband’s Labour party fell 24 seats to 232 and the Tories’ former Liberal Democrat coalition partner fell from 56 seats to just eight. Up north, the upstart Scottish National Party went from six seats to 56, leaving the three other major parties with just a single seat apiece in Scotland. (Message delivered.)

The prospect of another five years of Tory rule gave UK markets their biggest gains since January. Publicly traded bookmakers – particularly those with retail operations – were among the biggest gainers. William Hill rose nearly 6% on Friday and Ladbrokes was up 10%. And, as testimony to the theory that a rising tide lifts even leaky boats, Bwin.party was up 4%.

Not that the Tories have been particularly kind to bookies. The Conservatives instituted the new 15% online point of consumption tax and boosted the Machine Games Duty to 25%. But Labour had made it part of its manifesto to impose a new sports betting levy, plus further curbs on betting shops and their dastardly fixed-odds betting terminals.