The last few days have been downbeat for the semiconductor space. Three big semiconductor ETFs including VanEck Vectors Semiconductor ETF SMH, iShares PHLX Semiconductor ETF SOXX and Invesco Dynamic Semiconductors ETF PSI lost about 2.8%, 2.7% and 2.8%, respectively, in the last ten days (as of Jun 20, 2018). This was against a 0.1% dip in the S&P 500-based fund SPY.The movement was more prominent for the asset-flow corner. The fund SMH saw about $720.7 million in assets gushing out from Jun 10 to Jun 16. The outflows were about "45% of the total assets invested in the fund", per etf.com. At present, the fund has about $632.0 million in assets.On the other hand, SOXX lost about $67.1 million in assets, SPDR S&P Semiconductor ETF XSD saw an inflow of $7.6 million and PSI saw neither net inflow nor outflow. Let’s delve a little deeper to find out what hurt SMH so bad.Tariff Tantrum: A Headwind for Semiconductors in General Such movements in semiconductors were due to President Donald Trump’s $50 billion levy on Chinese imports, which has been retaliated by a Chinese levy on an equal worth of goods, including U.S. crude and gasoline.Both will now enact a 25% tariff on each other’s $34 billion of goods from Jul 6. The remaining $16 billion worth of goods will be under public review. But the situation may take an ugly turn as White House plans to enact tariffs on an extra $200 billion worth of Chinese goods, if China keeps retaliating to U.S. tariffs(read: Time to Buy Defensive ETFs?).As the tariff tantrum has taken the global market in its grip, investors are busy assessing which segments will be at most risks. Here comes the semiconductor pain. Per Morgan Stanley equity strategists, “semiconductor and semiconductor equipment companies have the highest revenue exposure to China at 52%” and are thus exposed to maximum risks on rising trade tensions (read: Apple's iPhone Order Cut Report May Hurt These ETFs).Chipmaker Qualcomm QCOM has 65% revenue exposure to China, and optical components manufacturer Lumentum LITE) has 23% exposure. Per Goldman Sachs, Nvidia (NVDA)’s sales exposure to China is 56%. Apart from these, some other tech and semiconductor companies, which have sales exposure to China in the range of 22% to 55%, include the likes of Intel INTC, Micron Technology (MU and Applied Materials AMAT. This clearly explains why the mood is somber in the semiconductor space.Why Asset Flow of SMH Was Especially HurtPer an article published on etf.com, both SMH and SOXX are liquid, but SMH has defeated SOXX in terms of average liquidity. Average daily trading volume of SOXX is more than 5.7 million shares while Average volume of SOXX is about 650,000 shares. Average daily volume of XSD and PSI are nearly 135,500 and 80,100 shares.Such solid liquidity encourages investors to track the tariff-related developments and “the day-in, day-out performance of the semiconductor sector” via SMH more than SOXX. Investors mainly targeted SMH to follow the downbeat performance in the semiconductor sector last week thanks to the vehicle’s greater efficacy on a short-term basis.Investors should note that higher average trading volumes result in a tighter bid/ask spread ratio and lower trading costs. So, when the broader semi-market recoils, there is high chance SMH will see solid inflows. Moreover, SMH (0.35%) has a lower expense ratio than SOXX (0.48%). This is another reason that can revive potential inflows in SMH in the long term.Want key ETF info delivered straight to your inbox?Zacks’ free Fund Newsletter will brief you on top news and analysis, as well as top-performing ETFs, each week. Get it free >>Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report QUALCOMM Incorporated (QCOM): Free Stock Analysis Report SPDR-SP 500 TR (SPY): ETF Research Reports SPDR-SP SEMICON (XSD): ETF Research Reports Intel Corporation (INTC): Free Stock Analysis Report Applied Materials, Inc. (AMAT): Free Stock Analysis Report To read this article on Zacks.com click here. Zacks Investment Research Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report