Ten bagger baseball explanation

Solution 1:

I think "bagger" is related to farming. You harvest 10 bags of wheat from 1 bag sowed which is analogical to investing.

Solution 2:

The Wikipedia link given in Adel's answer is spot-on, but the additional explanation misses the mark.

Sports (and martial) metaphors are big in the business world. In baseball slang, a "two bagger" is a double and a "three bagger" is a triple. So an investment that doubles your money would be a "two bagger", and one that triples your money would be a "three bagger". By extension, an investment that returns ten times your investment would be a "ten bagger"—even though that's quite impossible in baseball (at least under the current rules).