Tangentially related, I think it's interesting that people used to cite VOO pretty often, and IVV sometimes, but now I almost exclusively see SPY as an analog f

Tangentially related, I think it's interesting that people used to cite VOO pretty often, and IVV sometimes, but now I almost exclusively see SPY as an analog for the S&P 500. I wonder how much of it's high volume is just that it has the letters "s" and "p" in it?