Please note that although we respect frugality over lavishness. Frugality among rich people is one of the primary reasons behind wealth inequality. Sitting on top of an perverse amount of wealth and not doing anything with it is bad for the economy. Wealth needs to be redeployed back into the economy and it must be done in following a method that doesn't grow the wealth in an unnatural compounding way.
What are you exactly saying? Isn't 'redeploying money back to economy' basically investing? I think what you first would want is an increase to minimum pay if you want to increase the flow of money in the areas where I think you want.
Unless the stock is an IPO, you are essentially trading paper when you buy a stock. No GDP is generated on that transaction. In a sense you could be redeploying if the seller of the stock takes the money from the trade and redeploys it in a meaningful way.
I agree that rich people paying their workers more money is a meaningful way to redeploy their wealth.