Best U.S. Fund Managers of '18 Buying Healthcare, Pot Stocks as Market Wobbles

The top-performing U.S. growth fund managers of the last year are taking the recent slide in the U.S. stock market to add to their bets in companies they expect will continue to expand regardless of the direction of the overall economy.Among their top bets: life science companies like Biogen Inc , laboratory supply company Thermo Fisher Scientific Inc , and Canadian cannabis company Tilray Inc . The bullishness comes at a time when U.S. stock investors must weigh a strong domestic economy against the threats to growth posed by rising interest rates and a global economic slowdown exacerbated by higher trade tariffs between the United States and China, the world's largest economies.The S&P 500 tumbled in the fourth quarter, edging close to the 20 percent decline from its high that would signify a bear market. Since hitting a low on Christmas Eve, the broad market is up nearly 11 percent."In a nutshell, we think very little has changed," said Tom Slater, a portfolio manager of the $11.2 million Baillie Gifford U.S. Equity Growth fund, which has beaten the benchmark S&P 500 by 13.3 percentage points over the last 12 months. "There's a lot of doom and gloom in financial markets but we see fairly little evidence that doom and gloom is merited."As a result, Slater is sticking with companies like food delivery service GrubHub Inc and e-commerce platform company Shopify Inc that are innovating new business models or opening up old industries through innovation. "We're not massively interested in investing in technology but in new business models," Slater said.Anthony Zackery, a portfolio manager of the $127.6 million Virtus Zevenbergen Innovative Growth fund, said that his fund is eschewing some of the larger tech giants like Apple Inc that have led the broad market higher over the last few years and instead has been adding to its stake in tech companies such as identity management software company Okta Inc . Shares of the company are already up 12.7 percent since the start of January, adding to an approximately 160 percent rally over the last 12 months.