Summary It's certainly possible that oil prices will go even lower and remain depressed for many years to come; yet I doubt it. The selloff in biotech is overdone. The stock market is not dead. There is plenty of opportunity, if you know where to look. Stocks rallied strongly on the last day of September, but that wasn't enough to put them in the black for the month or for the quarter. Not even close. Despite Wednesday's gains, the S&P 500, the most widely followed index, fell 2.6% in September and fell a whopping 6.9% in the third quarter. That is the worst quarterly performance for the S&P since the third quarter of 2011, when it plunged 14.3%. If Yogi Berra were still with us, he'd probably say, "It's deja vu all over again." That's because many of the issues that hurt stocks in the third quarter of 2011 are still with us today. They include concerns about China's economy, worries about excessive debt in Europe, uncertainty about Federal Reserve policy, and fears of a possible government shutdown as the U.S. approaches its debt ceiling. Deja vu indeed. In general, September is the worst month of the year for stocks, and the third quarter is the worst quarter of the year. So I guess you could say that the good news is that October has arrived and so has the fourth quarter. Although the common wisdom is that October is the month to be feared, and stocks have had some of their biggest losses in October (down 16.8% in 2008 and down 21.8% in 1987), on average, stocks have generated a positive return of 0.7% for the month of October. Better still, stocks tend to rally even more in November and December, up an average of 1.4% and 1.6%, respectively. As a result, the fourth quarter tends to be the best quarter of the year. So here we are. This all should provide comfort to investors who fear that the recent stock market correction (typically defined as a 10% selloff from the high) will turn into a full-fledged bear market (defined as a selloff of at least 20% from the high). With Wednesday's rally, the S&P 500 managed to get out of correction territory, but barely. It is currently down 9.9% from its May 21 closing high. Nonetheless, many individual stocks are already in a bear market. On Tuesday, prior to Wednesday's strong rally, just over half the stocks in the S&P 500 were down more than 20% from their highs. Indeed, there have been some exaggerated selloffs, creating what could be excellent buying opportunities for patient investors: Energy is a sector that has suffered some of the biggest losses. Oil-related stocks have been crushed due to the previously unimaginable plunge in oil prices, which are down by half in just a year. It's certainly possible that oil prices will go even lower and remain depressed for many years to come; yet I doubt it. Why? The demand for oil is still growing. Eventually, the demand will catch up with supply, which is leveling off. When that happens, oil prices will return to the $60 to $80 per barrel range. No doubt Elon Musk is praying for higher oil prices. His company, Tesla Motors (NASDAQ:TSLA), just introduced an electric SUV with a price tag exceeding $100,000. Even though Tesla has plans to produce a cheaper electric car, Musk knows that there won't be a critical mass of drivers willing to give up their internal combustion engines if gasoline remains near $2 per gallon. If you expect oil prices to eventually recover as I do, you should consider buying the Energy Select Sector SPDR Fund (NYSEARCA:XLE), an exchange-traded fund that is heavily-weighted toward Exxon Mobil (NYSE:XOM) and Chevron (NYSE:CVX). Biotechnology is another sector that seems oversold. Biotech stocks have suffered due to the greed of one company that isn't even publicly traded. As I've explained before, Turing Pharmaceuticals jacked up the price of a 62-year old drug by almost 5,500%. Turing is not the only company to have raised prices after acquiring the rights to an existing drug, but what Turing did was especially egregious. Not surprisingly, politicians, including presidential candidate Hillary Clinton, are talking about imposing more regulation on the industry. That got investors worried and prompted them to sell biotech stocks like crazy. New regulations, however, are not likely to take aim at companies that already invest heavily on research to develop new drugs. Instead, regulations will target companies like Turing that simply buy the rights to sell existing drugs. As a result, I believe the selloff in biotech is overdone. Once again, a good way to invest is through an exchange-traded fund. I suggest the SPDR S&P Biotech ETF (NYSEARCA:XBI). It's a highly diversified fund with 100 holdings, yet its largest holding accounts for just 1.2% of the fund. Yogi Berra, who left us last week at the age of 90, once said, "You should always go to other people's funerals. Otherwise, they won't go to yours." That might be good advice, but despite the negative sentiment and a rough third quarter, the stock market is not dead. There is plenty of opportunity if you know where to look. More