Yesterday we saw substantial upside call activity in the largest Gold tracking ETF, GLD (SPDR Gold, Expense Ratio 0.40%) involving the June 117.50 calls in good size, with more than 100,000 contracts trading.

Interestingly, in the past month the ETF has seen decent outflows, with about $900 million leaving the ETF via redemptions. In spite of the outflows, GLD remains the largest Gold tracking fund by a mile, with more than $27 billion in assets under management.

IAU (iShares Gold, Expense Ratio 0.25%) is the second largest fund in the category with $6.3 billion in AUM and also worth watching closely in the near term given the call interest in GLD. With GLD trading with a $114 handle today the 117.50 strike calls would be in the money with an approximately 2.6% rally in Gold prices between now and June options expiration (6/19/15).

For what it is worth, GLD is trading below its 50 day MA currently after trading higher than $117 just nine trading sessions ago, as Gold prices have softened in the past week or so. Given the interest in upside call options, which of course is a leveraged long motivated trade, it also makes a ton of sense for us to closely monitor the levered long Gold ETPs that are periodically popular in the space.

These particular funds are DGP (PowerShares Gold Double Long ETN, Expense Ratio 0.75%), UGL (ProShares Ultra Gold, Expense Ratio 0.95%), and UGLD (VelocityShares 3X Long Gold ETN, Expense Ratio 1.35%). None of these funds are gigantic in terms of asset sizes, as DGP has $122 million in AUM, UGL has $91 million in AUM, and UGLD is the smallest of the three with about $38 million in AUM.