"They are able to identify your desire to buy shares in Microsoft and buy them in front of you and sell them back to you at a higher price," Lewis, whose book is available on Monday, said on the television program "60 Minutes" on Sunday.

I'm guessing the net effect of this is that you get trades for a few cents more than they would cost you otherwise. I guess "otherwise" means a perfect world where Goldman Sachs is a charitable organization run by Mother Teresa directing a band of angels.

This might be an issue for day-traders but if you're a buy and hold investor aiming for doubling or tripling of your holdings over years-decades, this small fractional cost at inception is likely negligible. (Which is not to say that the stock market is a safe place to be - there are many other cons to be aware of if you're a buy and hold person - insider trading, bad quality earnings, etc.).

It was not that long ago that investors were stuck with paying high commissions equivalent to several percentage points to acquire a stock. Now you can get 1000 shares of anything for $5. And maybe a few dollars more to line the pockets of HFT firms. Things seem better to me now on the whole.