probably a contract -> or the ETF shifts its holdings into IBIT, quite possibly. And yes, Zweig makes a sly remark about the transaction fees too, easily eating up whatever alpha may or may not exist there

that's usually the case with most "overperformance" found in models, theory, or backtesting... perhaps there's a bit to gain, but trading on it a) obliterates it by shifting prices around (e.g., January effect; publishing effect), and b) costs enough in fees/slippage/taxes to kill the entire trade