The phrase "ultimate hedge" refers to a strategy or action taken to protect oneself against possible risks or losses. It is like a safety net that helps ensure that you are not negatively affected by certain events or situations. Full definition
Buying an annuity — a lump sum you pay to an insurance company in exchange for a lifetime income — is the ultimate hedge against longevity. (canadianbusiness.com)
U.S. Treasuries are also regarded as the ultimate hedge against geopolitical risks. (blackrockblog.com)
One has so much cash on hand that trying to convince them to do something with that cash hoard has become the ultimate hedge - fund pastime. (news-to-use.com)