Easy. The stock markets are casinos. Moves that last less than a week or 2 are based on speculation and promotion, and in recent years program trading that amplifies whatever might start a trend both up and down. Sometimes, the programs get messed up and cause a "flash crash" too. Simply confirms that stock markets, while useful for long-term investments, usually lose money for average investors in the short term, or who are unlucky about when they buy or sell (see: casino). Average investors tend to get taken to the cleaners by the artists. Which is why, combined with obscene management fees, so many 401Ks do so poorly.

If all the RRs are going up, it might be time for looking at my exit strategy. Fast moves like what's been happening recently tend to be short-lived ... profit-taking almost certainly will occur in January, as usual. Even more so if the prospect for Trump's tax cuts looks good (holding until next year to get the better rates).