Delta-one
Perfectly hedged; a delta of one. Refers to a hedging strategy where a counterparty providing derivative exposure to an underlier by buying that underlier. You only need to delta-hedge your net exposure to the underlier - if, for example, you have written a long and a short TRS on the same underlier in the same size, you are delta-one hedged without buying anything - the two positions net each other off, and therefore hedge each other, exactly.