If investors feel like Nurse Diesel is about to pull away their fruit cup, it would be understandable. I refer, of course, to Mel Brooks' classic 1977 film "High Anxiety", and the unforgettable Cloris Leachman. It's getting harder for investors to shrug off their fears of a trade war, rising interest rates, vertiginous valuations for tech leaders, rising oil prices and about 100 other fear factors. The Investopedia Anxiety Index's Market readings are hotter than a lobster boil as searches for terms like short selling and bear market on our site have grown precipitously in the early days of summer. To be sure, our readers have been refreshing their sell-off vocabulary all year preparing for what they think is an inevitable market correction or worse. We can't and won't say that it will happen because we don't know when—or whether—it will. We know it's bound to happen because that's how markets behave, but trying to time it is a surefire way to get burned.

(Image: 20th Century Fox)

What we do know is that investors have been moving their money aggressively out of stocks, especially lately. Stats from Bank of America Merrill Lynch indicate that investors yanked nearly $30 billion out of equities last week—the second-highest weekly outflow ever—and pumped money into Treasury Bills. According to TrimTabs Investment Research, global equity funds were on track for their biggest monthly outflows since September of 2016, and have been steadily diminishing since January. Global equity mutual funds shed $6.8 billion this month through June 15 while global equity ETFs have shed a combined $9 billion in May and June.

Political rhetoric and trade war threats aren't helping quell the fears, either. It's not like we should be surprised by President Trump's stance on trade. It was one of the hallmarks of his candidacy and he is proving to be a man of his word on that matter. His most recent threats of having the U.S. leave the WTO are very serious, though. It is the one and only organization that attempts to bring predictability and order to the 164 countries who trade hundreds of trillions of dollars with each other and keep factories from Dayton, Ohio to Kyoto, Japan humming. It may be just another threat, and investors seem to have shaken it off today—at least in the U.S., but these things add up, and sometimes boil over, leaving long-term investors with serious burns.

So far this year, it's been mostly the anxiety that hurts the most. The S&P 500 is basically flat year to date, but we investors have had the wind at our backs given tax reform and stellar corporate earnings. Companies have been using that largesse for stock buybacks, in large part, so the benefit has not been that widespread, except for a few of the biggest and strongest tech companies.

So what's a long-term investor to do in times of anxiety? We used to 'sell in May and go away...', but the days of cute market sayings are gone, my friends. Unpredictability, policy threats propagated through social media and irrationality are our neighbors at the beach this summer, and they play loud music and take up a lot of prime space on the sand. If you are not used to them yet, you will be... but don't let them cause you to lose your head. (Related: The Truth About "Sell in May and Go Away")

Stay disciplined, stay invested, stay diversified, and stay alert. Selling into the fear or pretending that you can time this or any market is a sure fire way to make sure you will certainly not get your fruit cup!