Last week was slightly downbeat for Wall Street on talks of a capital gain tax hike. The S&P 500 (down 0.13%), the Dow Jones (down 0.5%) and the Nasdaq Composite (down 0.3%) were all in the red last week but the Russell 2000 (up 0.4%) managed to stay in the green.Decent U.S. economic data points released lately and subdued U.S. treasury yields helped the market momentum last week, but talks of a capital gain tax hike caused some occasional selloffs too.As has been discussed for over a year, President Joe Biden is now likely to propose a plan to raise taxes on the richest Americans, including the largest-ever increase in levies on investment gains (read: What Holds for ETFs If Biden Hikes Capital Gain Tax?).The proposed marginal 39.6% rate would be a substantial increase from the current rate of 20%, for those earning $1 million or more. Although markets rebounded soon enough to close out the week probably on hopes that Biden’s proposal may face opposition from Centrist Democrats in Congress, resistance from centrist Democrats might push the actual capital gain tax rate well below 39.6%.Against this backdrop, below we highlight a few ETF areas that topped last week.AgricultureCrop prices have been on an uptrend lately.A subdued greenback has kept overall commodity investing charged-up. Corn, soybean and wheat have all been pacing up. May corn futures touched the highest point since July 2013 thanks to China’s record corn imports due to crop failures and insufficient state reserves that have weighed on available global corn supplies.Meanwhile, wheat prices have been rising on weather concerns. MLCX Grains Index TR ETN Elements (GRU) (up 10.65%), Teucrium Corn CORN (up 8.93%) and Teucrium Wheat WEAT (up 8.3%) are some of the funds that surged last week(read: Corn ETF (CORN) Hits 52-Week High). ChinaChina stocks benefited last week as president Xi Jinping's renewed pledge for green energy boosted clean energy stocks while the global rise in coronavirus cases (especially in some Asian countries) aided the healthcare shares.KraneShares MSCI All China Health Care Index ETF KURE (up 9.27%), Loncar China Biopharma ETF CHNA (up 8.5%), Chinaamc Sme-Chn Vaneck ETF (CNXT) (up 7.54%) and Global-X MSCI China Health Care ETF (CHIH) (up 7.41%) were among the key winners in the space.SolarSolar Invesco ETF TAN was up 6.4% last week on a global pledge for transition toward clean energy. China’s president Xi reiterated his vows to turn his country carbon neutral by 2060. China will start tapering coal use from 2026, Xi said last week. In the United States too, President Biden is voicing for clean energy transition. Europe’s efforts to become a green continent is also pretty prevalent. All these factors helped TAN last week.ShippingBreakwave Dry Bulk Shipping ETF BDRY seeks to provide investors with exposure to the daily change in the price of dry bulk freight futures. It added 4.6% last week. The pickup in global economic growth has supported the dry bulk shipping rates. Gradually rising demand across all vessel categories has mainly aided the area and the related fund (read: Top-Performing ETFs of March).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 INVS-SOLAR PRT (TAN): ETF Research Reports BRKWAVE-DBS ETF (BDRY): ETF Research Reports KRANS-MS CHN HC (KURE): ETF Research Reports LONCR-CHINA BIO (CHNA): ETF Research Reports 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