Shares in exploration company UK Oil and Gas (UKOG) exploded after the discovery of up to 100bn barrels in its oil field in Sussex.
UKOG's Aim-listed shares gushed higher than an oil well - up more than 300 per cent at its highest in early trading and closing 164 per cent up for the day.
The gains take UKOG shares to an all-time high, surpassing a previous high of 1.8 pence per share seen in October before global oil prices plummeted.
Horse Hill is one of the oil and gas firm's three investments. Specialising in UK investments, the firm has a 30 per cent stake in Horse Hill Development, the company which holds a 65 per cent interest in this oil field in the Weald Basin in the south east of England.
It also holds an interest in Horse Hill and two other developments in the Weald through a six per cent stake in Angus Energy.
Horse Hill Development is a consortium of several firms working on the site, which also includes Solo Oil, Regency Mines, Alba Minerals, Stellar Resources, and Doriemus in addition to UKOG.
Shares in Solo Oil were up more than 30 per cent, while shares in Alba Minerals rose 155 per cent, Stellar Resources rose 68 per cent and Doriemus shot up more than 70 per cent at pixel time.