Shark Tank star Kevin O'Leary, chairman of O'Shares ETF Investments, said volatility is back.

"Everything old is new again. We've got volatility back just like we used to have ten years ago," O'Leary said to TheStreet, adding that strong U.S. economic fundamentals bolster the argument for putting more money into mid-cap U.S. stocks.

O'Leary's (OUSM) exchange traded fund tracks high quality Russell 2000 stocks with strong balance sheets. 

U.S. companies aren't as affected by trade issues as large multi-national companies are, according to O'Leary. 

 

More from Video

Canopy's CEO and Constellation Brands COO Discuss the Many Uses of Cannabis

Canopy's CEO and Constellation Brands COO Discuss the Many Uses of Cannabis

Even the Fashion World Suffers From the Ol' Boys Club

Even the Fashion World Suffers From the Ol' Boys Club

The Federal Reserve Is in Uncharted Territory and Is a Risk to the Bull Market

The Federal Reserve Is in Uncharted Territory and Is a Risk to the Bull Market

This Market is Comparable to Getting Into a 'Fist Fight'

This Market is Comparable to Getting Into a 'Fist Fight'

Investing for Retirement? Consider Socially Responsible Investing

Investing for Retirement? Consider Socially Responsible Investing