> The second cash sweep that will happen actually happens overnight. You will see this listed as "Cash Sweep" in ThinkorSwim. This overnight sweep is used to get the futures cash balance high enough to cover the exchange's initial requirement which is posted by the CME. As of today, for /MES the exchange initial requirement is 2,412.3 per contract for longs, however this does change every day. The overnight sweep moves the cash, so the futures cash balance equals the exchange initial requirement.
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Some useful threads:
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- [How do rolling and margin on futures trading work?](https://www.bogleheads.org/forum/viewtopic.php?t=300111)
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### Futures instead of stock
Futures let you buy (or sell) into indexes like the S&P 500 and Russell 2000. A long /ES or /MES futures position should be equivalent to holding SPY shares. It is essentially an ETF without fees, however the longer-dated future price will be higher than the current index. There is an inherent loan when you long a future, and that interest is baked in.