Still recovering from last week's stock market volatility? It's not over yet, according to one market expert. Stock market investors should prepare for some bumpy sessions in the next few weeks, according to Brian Jacobsen, Chief Portfolio Strategist at Wells Fargo Advantage Funds. Jacobsen looked at 25 past previous bull market corrections and found that they usually lead to even more volatility in the days that follow. 'Typically the next twenty days out, you have heightened volatility of around twice what you had going into the correction,' said Jacobsen. 'So I think that investors and traders can brace themselves for some of these bigger moves.' The bout of renewed volatility will come just as the Federal Reserve prepares for a crucial two-day interest rate policy meeting. Jacobsen is expecting the Fed to announce a rate hike in mid-September, and said that the stock market is beginning to price that in. 'The nice thing about the market move that we saw last week and the week before is that from a valuation perspective, the stock market is in a much better place to absorb a rate hike,' said Jacobsen. TheStreet's Rhonda Schaffler has details from New York.