I am attempting to obtain monthly data for several asset classes dating back to 1970, which can be used as a proxy for various ETFs such as:
EEM
TLT
SPY
GLD
PDBC (dbc)
VNQ
I’ve found something here: https://www.investing.com/commodities/gold-historical-data
However, does anyone know of any other sites where long-term, monthly asset class data may be found?