It's not a parable about literal money. Like Jesus speaking to Nicodemus in John 3, Jesus is using the literal, physical world--the things we can understand--to explain the spiritual. Over and over again in the scriptures God uses analogies and metaphors and the like to teach unseen, spiritual principles to the earthbound minds of fallen men.
"I have spoken to you of earthly things and you do not believe; how then will you believe if I speak of heavenly things?" (John 3:12)
Maybe this proverb sums up the parable of the talents:
"The wages of the righteous bring them life, but the income of the wicked brings them punishment." (Proverbs 10:16)
Even if the parable of the talents had a literal meaning there is nothing wrong with putting our "money to work" (vs. 16). Playing the market is only one way of bringing increase to money. You can buy things and sell them at a profit, or produce products to sell at a profit as long as we do it honestly and don't violate any of the Lord's commands.
"Lazy hands make a man poor, but diligent hands bring wealth."
"He who works his land will have abundant food, but he who chases fantasies lacks judgement." (Proverbs 12:11)
"Dishonest money dwindles away, but he who gathers money little by little makes it grow." (Proverbs 13:11)
"The Lord abhors dishonest scales, but accurate weights are his delight."