• Investments by a Fund in options, futures, forward contracts, swap agreements and other derivative financial instruments are subject to numerous special and complex tax rules. These rules could affect the amount, timing or character of the distributions to shareholders by a Fund. In addition, because the application of these rules may be uncertain under current law, an adverse determination or future Internal Revenue Service guidance with respect to these rules may affect whether a Fund has made sufficient distributions, and otherwise satisfied the relevant requirements, to maintain its qualification as a regulated investment company and avoid fund-level tax.
There's a lot of ins and outs which can get confusing in arbitrage trading. We won't go into the technicals of why futures contracts trade at a premium to spot price. You can read a full explanation here. If it's not of interest to you, all you need to know is that there's a tendency, the further out in time the futures contract expires, for the premium to spot to be higher and higher in nominal percentage terms.