We investigate models of the life annuity insurance when the company invests
its reserve into a risky asset with price following a geometric Brownian motion. Our main
result is an exact asymptotic of the ruin probabilities for the case of exponentially distributed
benefits. As in the case of non-life insurance with exponential claims, the ruin probabilities
are either decreasing with a rate given by a power function (the case of small volatility) or
equal to unit identically (the case of large volatility). The result allows us to quantify the
share of reserve to invest into such a risky asset to avoid a catastrophic outcome: the ruin
with probability one. We address also the question of smoothness of the ruin probabilities
as a function of the initial reserve for generally distributed jumps.