Resolves YES if price at CLOSE on Friday is higher that price at OPEN on Monday, for the S&P 500 tracking index during the current week (taken from Yahoo finance ^GSPC)

Open price for Mon 9th Sep was 5442,07

This is my first market, I'm making it mini, but I plan on repeating this every week so if it becomes popular and I can afford to fund it better I'll improve the tier in the future, also I put the close on Saturday in case I can't resolve this Friday night.