Wall Street was upbeat last week with the S&P 500, the Dow Jones, the Nasdaq Composite and the Russell 2000 adding 0.6%, 0.7%, 0.5% and 0.8%, respectively. Small-cap stocks are on a tear amid post-pandemic recovery (read: Small Caps Enjoy Longest Run Since 1995: 5 ETF Winners).Against this backdrop, below we highlight a few ETF areas that won last week.EnergySeveral energy stocks gained last week on two-year high oil prices. COVID-19 cases have declined in the United States. More than half the U.S. population has received at least one dose of COVID-19 vaccination, according to data posted by the Centers for Disease Control and Prevention, as quoted on CNBC. Higher oil prices are beneficial for oil companies (read: ETFs to Gain as Oil Rallies on Upbeat Demand Outlook).Oil market watchers expect a recovery in oil consumption on the back of growing vaccination and economic reopening. With supplies remaining controlled and demand improving, oil prices could continue rallying. Microsectors U.S. Big Oil Index 3X ETN (NRGU) – Up 21.8%S&P Oil & Gas Expl Bull 3X Direxion (GUSH) – Up 16.99%Natural Gas ETF FT (FCG) – Up 9.7%BrazilStrategists at Citi wrote in a client note that the general belief is recent revisions to growth and inflation in Brazil, and better fiscal numbers will outdo emerging “political stories," as quoted on Reuters. Such sentiments probably have boosted Brazil’s stocks.Brazil Bull 3X Direxion BRZU – Up 18.6%Ultra MSCI Brazil Proshares UBR – Up 18.56% Real EstateThe U.S. real estate market has been red-hot as a rising stock market and its consequent wealth effect have strengthened the spending power of the wealthy. This, in turn, has boosted the real estate values. Low inventories and higher demand have also boosted property prices. Cheap mortgage rate is another positive. Real estate stocks’ higher dividend yield is another attractive point. As of Jun 4, 2021, the benchmark treasury yield was 1.56% versus 1.62% noted on Jun 1, 2021. Such low rates helped the rate-sensitive real estate stocks gain last month.Real Estate Bull 3X Direxion DRN – Up 10.3%South KoreaSouth Korean shares recorded awesome weekly gains. Foreign buying led to this euphoria. South Korea’s May exports are expected to have increased at their fastest pace in over three decades, partly due to strong global demand for the nation’s key foreign exchange earners such as semiconductors, cars and petroleum products.South Korea Bull 3X Direxion KORU – Up 9.6%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 DIR-D BRZL BL3X (BRZU): ETF Research Reports DIR-D S KR BL3X (KORU): ETF Research Reports DIR-D RE BULL3X (DRN): ETF Research Reports PRO-ULT MSCI BR (UBR): 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