put it in your bank and in like 70 years you'll have crazy interest
If you put the $150 into the bank this year and waited 70 years (not putting any more money in at all) and assuming you got a 4% annual compound interest you would end up with
$2335.74If you added $100 each year with the same interest rate you would end up with...
$40,221.95 Unfortunately...with a 6% average annual inflation rate...it means jack stuff.
You'd have better luck investing the money in other ways.