Its six consecutive record closes through October 5 was the longest such winning streak for the S&P 500 Index (SPX) since 1997, according to CNBC. Meanwhile, a signal that the market is heavily overbought comes from the relative strength index (RSI), a widely-used measure of stock price momentum. Worried investors are increasingly using call options on the CBOE Volatility Index (VIX) to hedge against a market selloff, Barron’s reports. Another indicator of investor sentiment, the Investopedia Anxiety Index, was registering high anxiety about the global economy as of October 6, but a neutral opinion of the markets.

Widespread Overbuying

The RSI is a popular momentum indicator that attempts to capture both the speed and magnitude of asset price movements in a single number, with the default measurement period being 14 periods, most often 14 trading days. Values are on a scale of 0 to 100, with readings of 70 or above traditionally interpreted as signifying an overbought situation wherein prices have raced ahead of the fundamentals, increasing the likelihood of a…