With Hormuz still shut, options market signals rising risk of $150 oil 

* Options market shows bets on $150 oil by end-April rising

* Open interest in $150 calls nearly ​10 times ⁠larger than last month

* Oil is trapped in Gulf following U.S.-Israel ​conflict with Iran

* Brent crude set all-time high of $147 in 2008

LONDON, March 26 (Reuters) - Traders are piling into oil options betting Brent crude will surge ​to ‌an all-time high of at least $150 a barrel by the end of April, as the war in the Middle East continues to choke supplies through the Strait ⁠of Hormuz.

Brent, which is currently trading around $107 a barrel for May, has shot up nearly ⁠50% since February 28, when the U.S.-Israeli war against ​Iran broke out, effectively blocking oil transit through the Strait of Hormuz. Prices remain volatile despite tentative signs that Washington and Tehran are looking for a way to end the conflict. Options trades in the derivatives market show bets have risen tenfold in the last few weeks on oil hitting at ​least $150 a barrel ‌by the end of April, as traders position themselves for near-term volatility. That would surpass Brent’s record high of $147 a barrel set in 2008, when booming demand strained supply capacity.

Data from ICE shows ownership of the contracts which expire at the end of April and give the holder the option to buy June Brent futures at $150 - known as call options - is almost 10 times larger than it was a month ago. "These ​calls are clear signs that investors see tail risk outcomes to the current conflict and are increasingly trying to manage those outcomes," Tim Skirrow, ‌head of derivatives and energy at Energy Aspects, said. "$150 a barrel oil will certainly cause a demand shock but as long as oil cannot flow out of the Gulf there will be risks of ‌outright shortages."

BETS ON $150 AND ABOVE MOUNTING

Open interest for April expiry $150 call options has risen to 28,941 lots, each representing 1,000 barrels of oil. Based on the current crude price, that would equal nearly $3 billion worth of crude. A month ago, there were just 3,374 lots in open interest ​for $150 calls. The data did not show how many investors are holding these options, nor was their identity clear. Open interest in options to buy oil at $160 has gone ‌from zero to 14,676 lots, equal to around $1.5 billion of crude, while open interest in calls between $200 and $240 is equal to around $1 billion. There is even limited interest in $300 June calls.

Despite the rising bets on $150 a barrel crude, the largest holding is by those with options to buy oil ⁠at $100, with ⁠61,594 lots of open interest.

WIDE RANGE OF OUTCOMES POSSIBLE Roughly one-fifth of the world's daily oil supply ‌is currently trapped in the Gulf, which has pushed everything from the price of physical oil, to the cost of transporting and insuring it, to multi-year, or even record highs. ​Any sign of a meaningful pickup in ​marine traffic through the Strait of Hormuz is likely to result in markets reevaluating prices.

Ownership of ‌put options expiring in late April is concentrated well below current levels, with the most open interest between $45 and $70 a barrel. While positions in those strikes have also increased, the buildup has been far slower than in upside calls, suggesting investors see extreme outcomes in both directions but think there is a higher probability of further price spikes. (Editing by Alex Lawler and Elaine Hardcastle)