Kia is the safest bet for investors in a recent study.

Bloomberg announced today that it rates Korean automaker Kia at the top of its Riskless Return Ranking, a study that suggests the brand is the safest investment among all 22 publicly-traded major global automakers.

Based on the last five years, Bloomberg says that Kia gave investors a risk-adjusted return of 9.2 percent. That's the highest of any brand in the Bloomberg World Auto Manufacturers Index of 22 automakers, and it's not only a sign of Kia's stability, it's an indication of how far the automaker has come.

Bloomberg gave a similarly positive, albeit not as strong risk-adjusted return 4.8 percent to Hyundai, which owns about half of Kia.

The financial gurus at Bloomberg said that they calculate automaker risk-adjusted returns by dividing total returns by volatility (the degree of daily price-swing variation). A higher volatility, Bloomberg says, indicates that the automaker's share prices can swing "dramatically," which increases the chance of losses.

While Bloomberg's analysis that Kia's volatility topped all automakers in emerging markets (think China and India in addition to South Korea) damns the brand with faint praise, Bloomberg does note that Kia "posted higher absolute returns" than any rival anywhere.

Kia's big gains have come primarily in its home market, North America and Europe, but the automaker expects sales to begin to level off as rivals step up their game.