ZSP holds the S&P 500 at a 0.08% MER — making it the cheapest broad US-equity ETF available to Canadians. 0.01% cheaper than VFV. Same index, same companies. The choice between ZSP and VFV is purely a provider preference (BMO vs Vanguard) and which ETF lineup you already own.
BMO offers three S&P 500 ETF flavors: ZSP (unhedged, base CAD), ZSP.U (USD-denominated, US dollar buying), and ZUE (CAD-hedged). They all track the same index — but hedging dramatically changes your CAD-denominated returns.
Holds S&P 500 in USD. Your return = stock + (USD/CAD movement). Best for long holds — historically USD strengthens against CAD.
Same fund, priced in US dollars. Good for "buying USD" via your Norbert's Gambit or holding in a USD account.
Strips out USD/CAD movement. Your return = ONLY US stock performance. Best if you fear USD weakness.
If you already hold BMO ETFs in BMO InvestorLine (free trades), ZSP is the natural pick. If you bank with Vanguard's ecosystem or use a robo, VFV makes more sense. Performance differences are within rounding error.