18. The SPY and the GSPC are both indexes of the S&P 500. Although, the SPY is an index fund (a stock that can be bought and sold) and has an ex-dividend on the third Friday of the last month of each quarter (coincidently also a monthly options expiration date, although the SPY has options that expire on Mondays, Wednesdays, and Fridays). Open Yahoo Finance and Compare the SPY and the GSPC in a 5 day Chart. Why the difference in price on 06/19/2020 (scroll back)? I 18. The SPY and the GSPC are both indexes of the S&P 500. Although, the SPY is an index fund (a stock that can be bought and sold) and has an ex-dividend on the third Friday of the last month of each quarter (coincidently also a monthly options expiration date, although the SPY has options that expire on Mondays, Wednesdays, and Fridays). Open Yahoo Finance and Compare the SPY and the GSPC in a 5 day Chart. Why the difference in price on 06/19/2020 (scroll back)