Why a seller would skip listing publicly
Privacy (no yard sign, no strangers walking through), speed (no showing schedule to manage), and certainty (one negotiated buyer instead of an open, competitive process) are the usual reasons — often paired with a house that needs real work and would show poorly on the open market anyway.
Why investors specifically look for these
A listed property on the MLS gets competitive bidding from other buyers; an off-market property is negotiated one-on-one, which is why serious investors build direct relationships with sellers, agents and other investors rather than relying only on public listings.
What it isn't
Off-market doesn't mean unregulated or informal — a lawyer, title search and standard closing process still apply the same as any other real estate transaction in Ontario.