By Pete Najarian, co-founder of OptionMonsterNEW YORK -- Silver moved up again Thursday, and the options turned extremely bullish. Earlier in the week, investors were buying short-term calls in the iShares Silver ( SLV) exchange-traded fund in hopes of a quick rally. Now they're looking out to the spring, buying big blocks of the June 35 calls and June 36 calls for $2.20 and $1.9, respectively. The trades occurred less than an hour after the open, and both appreciated about 10% as the fund pushed higher. The fund ended the session at $34.40, up 2.87%. It has climbed 6% in the last week, following gold higher. Calls lock in the price investors must pay to buy a stock, so they can really appreciate if the fund moves in the right direction. If it doesn't, those same contracts will expire worthless. More than 228,000 calls traded in the SLV Thursday versus just 73,000 puts. Total volume was five times more than average. Najarian owns long SLV calls.