Stocks tumbled Wednesday, sending the Dow and S&P into the red for the year.The S&P 500 (^GSPC) dropped 3.09%, or 84.59 points, to close at 2,656.10. The index started the year at 2,673.61. The Dow (^DJI) fell 2.41%, or 608.01 points, to close at 24,583.42. The 30-stock index started the year at 24,719.22The Nasdaq (^IXIC) plunged 4.43%, or 329.14 points. However, the tech-heavy index is still up 2.9% for the year.