I think you're vastly underestimating how quickly markets change, how technically difficult it would be to provide breaking information fairly at the ten minute

I think you're vastly underestimating how quickly markets change, how technically difficult it would be to provide breaking information fairly at the ten minute mark and how important liquidity is to the market. If we slowed trades down then the economy would be significantly less responsive and markets in other countries would have significant advantages. Shorter answer: If I can gain a profit now instead of in 10 minutes I can reinvest just as quickly and the entire economy benefits. These small chunks add up.