Will S+P 500 investors bank gains in a shortened month-end session today?

The US stock markets were of course not open yesterday. The broadest measure of the US stock market; the S+P 500 last closed on Wednesday, at 5,998.74. The index had failed to set any fresh records that day, peaking earlier in the session, at 6,020.16. The S+P 500 had set a new all time high the day before, at 6,025.42 and set a record close that day, at 6,021.63. The S+P 500 futures are higher this morning though and right now pricing the opening close to the record levels set earlier in the week. The big question for today, seeing as it is the last day of the month, will investors bank gains in what is a shortened session today? The S+P 500 will close this evening at 6pm GMT instead of the usual close at 9pm GMT. For what it is worth, US bond markets will also close early, at 7pm GMT. There are no US data releases this afternoon to help guide the price action either. So, what chance another record close tonight? To be honest month-end rebalancing and significantly lower levels of participation might just get in the way of that, but we shall see later on. The index is currently priced to reopen around 6,019