This is not the start to the week investors had in mind. Stock futures indicated steep losses at the open after the worst trading day in Japan since 1987. The Nikkei 225 plunged 12.4% . European stocks were also under pressure. This global sell-off comes amid concerns over the state of the U.S. economy. Data released Friday showed 114,000 jobs were created last month, far below a Dow Jones estimate of 185,000. But it was more than just that data point. Investors are concerned the Fed is falling behind the curve. Overnight, traders are pricing in a half-point Federal Reserve rate cut for September. Some on the Street think the Fed should make deeper cuts. The S & P 500, accounting for Monday’s expected losses, will be down around 9% from its recent high. A move lower of 10% would be an official correction. Chart analyst Katie Stockton of Fairlead Strategies thinks a deeper correction is afoot. Here are the levels she is watching. She sees support emerging for the S & P 500 around the 5,000 level, or another 6.5% from here. If the benchmark breaks below that level, she sees support around 4,820. The index closed Friday at 5,346.56, so that would be another 9% from there. .SPX 1Y mountain S & P 500, 1-year “There’s a chance of a snapback even today, and if that does occur, as it did on Friday, that would increase the possibility of an oversold bounce,” Stockton told CNBC’s ” Squawk Box .” The major averages fell sharply on Friday, too, but closed well off their session lows. If market conditions get very dire in the meantime, there is a chance the Federal Reserve could step in, investors hope. Wharton School professor Jeremy Siegel told CNBC’s “Squawk Box” on Monday that the central bank should move forward with two 0.75 percentage-point rate cuts going forward — “and that’s minimum.” “The fed funds rate right now should be somewhere between 3.5% and 4%,” he said . “The market knows so much better than the Fed. They’ve got to respond.”