Investors increased bets that oil prices may surge to as much as $250 a barrel on concern the unrest in Egypt will disrupt traffic in the Suez Canal and spread to Saudi Arabia.

Open interest in the $250 call option for December, which give the buyer the right to purchase oil futures on the New York Mercantile Exchange at that price, climbed to 242 from 142 on Feb. 1 and stayed at that level yesterday. The most active options yesterday were the March and December $100 calls followed by the December $120 call.

“What we are seeing is similar to people buying a lottery ticket,” said Stephen Schork, president of Schork Group Inc., a consulting company in Villanova, Pennsylvania. “They are making a bet that there will be a disruption of the Suez Canal or an uprising in Saudi Arabia, neither of which looks likely.”