The month of October was all about a sharp stock market crash on rising rate worries and trade war fears. Overall, the S&P 500 registered 6.9% loss in October, marking its worst monthly performance since September 2011 and tech stocks underwent their worst month since the 2008 recession.Let’s delve a little deeper and see which ETF areas raked in the maximum in the month and which ones lost the most (per etf.com).S&P 500 RulesDespite crashes, the S&P 500-based ETFs drew copious assets. iShares Core S&P 500 ETF (IVV) topped the list with about $4.23 billion of monthly inflows. Another S&P 500-based ETF Vanguard S&P 500 ETF VOO garnered assets worth of $2.07 billion. However, SPDR S&P 500 ETF (SPY) lost about $4.97 billionprobably due to the fact it charges higher fees (0.09%) than the other two (0.04%).Communication at a Sweet SpotThe communication services sector has been newly minted and is the extended version of the old telecommunication sector.It has a lot of growth potential andhas now become riskier and cyclical with a new look.According to the State Street, the regrouping of companies in the new sector is expected to generate more than $30 billion in market activity, indicating potential upside for Communication Services Select Sector SPDR Fund (XLC). So, the fund attracted about $2.04 billion in assets.Japan ETFs on a Tear TooIn terms of assets, iShares MSCI Japan ETF (EWJ) took the fourth spot with about $1.72 billion of inflows. The market saw resurgence in investors’ interest of late, after months of outflows. The uptick in interest was noticed after the Nikkei 225 Stock Average jumped to a 27-year high in early October, while the yen dived to its weakest level against the dollar since November.Short-term Treasury ETFs Popular Among Investors Since these have very low duration, these are less susceptible to rising rate worries. Real returns of cash alternatives are improving. Yields on short-term Treasury bills outdo U.S. inflation, meaning investors can now have real, inflation-adjusted returns from cash for the first time in a decade, per Financial Times.So, SPDR Bloomberg Barclays 1-3 Month T-Bill ETF (BIL) and JPMorgan Ultra-Short Income ETF (JPST) added about $1.71 billion and $888.2 million in assets (read: Is Cash the Best Asset Right Now? ETFs in Focus).Long-term Bonds Fell FlatNeedless to say, longer-duration funds are more susceptible to rising rate concerns. So, investors dumped iShares Core U.S. Aggregate Bond ETF (AGG), iShares iBoxx USD Investment Grade Corporate Bond ETF (LQD), SPDR Bloomberg Barclays High Yield Bond ETF JNK and iShares 20+ Year Treasury Bond ETF (TLT), which saw about $2.64 billion,$2.07 billion, $2.06 billion and $1.68 billion of assets gushing out, respectively.Technology Not on Investors’ RadarOvervaluation concerns and rising rates were killjoys for the segment. Technology Select Sector SPDR Fund (XLK) shed around $1.02 billion in the month.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 VANGD-SP5 ETF (VOO): ETF Research Reports SPDR-TECH SELS (XLK): ETF Research Reports ISHARS-CR US AG (AGG): ETF Research Reports ISHARS-IBX IG (LQD): ETF Research Reports SPDR-BBC 1-3M T (BIL): ETF Research Reports ISHARS-SP500 (IVV): ETF Research Reports SPDR-BBC HY BD (JNK): ETF Research Reports ISHARS-JAPAN (EWJ): ETF Research Reports ISHARS-20+YTB (TLT): ETF Research Reports SPDR-SP 500 TR (SPY): ETF Research Reports JPM-UL SH INCM (JPST): 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