Not sure how they do it, but our recent experience indicates that Symetra is consistently at the top of the list in terms of longevity insurance pricing. In other words, their rates seem to be consistently higher than their competitors.
It does not appear to have anything to do with credit rating as the company maintains A ratings with both AM Best and S&P.
Deferred annuities account for 43 percent of the company's retirement division pretax adjusted operating income and they are a leader in deferred annuity market share (ranked 3rd), so somethign is clearly working for them.
The investment and related spread side of the equation is based in part on what they refer to as a commercial mortgage loan origination strategy that is intended to improve yield and stabilize spreads.
Maybe some of the magic is on the distribution side with heavy bank distribution, or maybe it is simply an overall well managed insurance company in the tradition of Berkshire Hathawat and White Mountains.