I can't comment directly on your particular holding, but I believe that is an ETF. ETF's are different than common stock and the one you have, like other commodity ETF's is based on the entire Futures Curve, meaning the ETF owns a certain amount of each contract on the Futures curve. So when the near term contract expires, they have to sell those contracts (to avoid taking or making delivery) and re deploy the money along the curve at certain prices (could be higher or lower depending on whether the curve is in contango or backwardation).
But to answer reverse stock splits. It could be to prevent from being delisted and being relegated to the pink sheets or the over the counter bulletin board.. Depending on exchange, stocks get delisted if they fall below a certain price. So by shrinking the float you increase the price per share, but total valuation remains the same.