Difference in price/point drop between SPY and SPX

Question

Usually, the ETF SPY tracks the S&P 500 Index rather closely. At the close of today, 12/16/2016, I noticed two things: 1. Most sites listed SPX down 3.96, and SPY down 1.77. Why such a big discrepancy?
2. Some sites listed SPY down .44, which would actually be more in line with the norm. Why would Yahoo and others list Spy down .44 with the majority of sites posting a 1.77 loss? Thanks.

Answer 1

Next 2016 SPY, VOO, IVV Ex-Dividend Dates and Estimated Dividends notes in part:

SPY went ex-dividend Friday, December 16th, 2016 with a dividend of $1.32893 per share. Its distribution payout will be on January 31st ,2017.

Note that SPX as an index doesn't count dividends and thus you have most of the difference you are looking for here.