NEW YORK (TheStreet) -- Last week's ugliness on Wall Street continued into Monday after China's stock market collapsed into negative territory for the year.

S&P 500 futures were down 3.75%, Nasdaq futures slid 5%, and Dow Jones Industrial Average futures dropped 4%. The Dow was on track to drop more than 600 points at market open.

China's Shanghai Composite plummeted 8.5% on Monday, its biggest one-day percentage decline since early 2007. The index crumbled more than 10% last week after manufacturing data supported fears the world's second-largest economy was undergoing a significant slowdown. 

World markets fell in-step with China's stock market. European markets such as Germany's DAX, France's CAC 40, and the FTSE 100 in London plummeted more than 4%, while Japan's Nikkei fell 4.6% and the Hang Seng slid 5.2%. 

Crude oil plummeted to its lowest level in six-and-a-half years on fears over demand from China. West Texas Intermediate was down 3.5% to $39.04 a barrel. The commodity was on track for its first closing price below $40 a barrel since 2009. 

High-momentum stocks were selling off on fears over China's economy. Apple (AAPL) fell more than 6% in premarket trading, Alibaba (BABA) slid 9%, Twitter (TWTR) tripped 6.9%, Google (GOOGL) slipped 4.8%, and Amazon (AMZN) fell 6.4%.

Casino stocks with exposure to Asian gambling destination Macau were sharply lower. Melco Crown Entertainment (MPEL) slid 13%, Las Vegas Sands (LVS) fell 7.3%, Wynn Resorts (WYNN) was down 7.7%, and MGM Resorts (MGM) tumbled 8.2%. 

The U.S. dollar made mixed moves against international currencies. The greenback was down more than 1% against the euro and Japanese yen, while spiking 1.2% against the Aussie dollar and 0.46% against the Canadian dollar. 

U.S. bonds saw increased demand on Monday as investors sought a safe-haven asset in light of the increased risk of equities. U.S. 10-year bond yields fell below 2% for the first time in 4 months, down to 1.97%.

Benchmark indexes closed their worst week in nearly four years last week as a continued slowdown in China spooked equity and commodity traders. The S&P 500 was down 3.2% for the day and 7.5% since its May high, near the 10% decline which would constitute a correction.

The other averages didn't do much better. The Dow Jones Industrial Average dropped 3.1% or 539 points, and down 10% from its May record, while the Nasdaq slid 3.5% and nearly 7% since Monday.