US STOCKS suffered their worst one-day loss in two months yesterday, dropping the S&amp;P 500 back into negative territory for the year in a broad-based sell-off, as investors reconsidered the health of the economy.<br /><br />A sharp drop in US crude oil futures and other commodities hit shares of companies sensitive to those prices, including <strong>Exxon Mobil</strong>, which lost 3.1 per cent to $68.84.<br /><br />The Dow Jones industrial average dropped 200.72 points, or 2.35 per cent, to end at 8,339.01. The Standard &amp; Poor&rsquo;s 500 Index was down 28.19 points, or 3.06 per cent, at 893.04. The Nasdaq Composite Index was down 61.28 points, or 3.35 per cent, at 1,766.19.<br /><br />The S&amp;P financial index fell 6.2 per cent, while the energy index dropped 4.6 per cent. The financial sector saw the biggest gains since the S&amp;P 500 hit a 12-year closing low in early March, and the sector is still up more than 80 for that period. The S&amp;P, meanwhile, is up 32 per cent from its March closing low.<br /><br />Crude oil prices fell $2.62, or almost 4 per cent, to settle at $66.93 a barrel. <strong>Chevron</strong> sank 3.4 per cent to $65.76.<br /><br />On the Nasdaq, big-cap technology stocks led the decline.<br /><br /><strong>Walgreen</strong> posted weak quarterly results as US shoppers focused on buying only necessities. The drugstore chain&rsquo;s stock fell 5.7 per cent to $29.64.