Investing ideas of bond master Jeffrey Gundlach – the founder of DoubleLine Capital LP – are imitable to many. His predictions at last year’s Sohn conference, which bids ace Wall Street investors to share their expertise, even returned 40%.Gundlach in fact appropriately predicted Donald Trump’s chances of winning the U.S. presidential election.Needless to say, such fascinating predictions and investment calls make it important to follow what Gundlach is saying now about the broader investing world. Below we elaborate a few such calls and their adjoining ETF picks for investors who are fans of Jeffrey Gundlach.A Bet Against the S&P 500Jeffrey Gundlach's DoubleLine Capital bought “some five-month put options on the Standard & Poor's 500 Index” as the CBOE Volatility Index is “ridiculously low.” The S&P 500 has spent over 265 days not seeing a correction of 5% or more and marked its longest winning streak in 20 years (read: 6 ETFs for a Historically Low August).He expects volatility levels to rise in the coming days probably because this high level of market complacency is weird. After all, the U.S. economy hasn’t seen any material reforms enacted by the Trump administration so far. So, any deepening in the political uncertainty related to Trump’s pro-growth policies could lead the broader market to a crash. In this light, inverse S&P 500 ETFs like Direxion Daily S&P 500 Bear 1x Shares ETF SPDN, ProShares Short S&P500 ETF SH and ProShares UltraShort S&P500 ETF SDS are likely to gain ahead. Volatility product iPath S&P 500 VIX ST Futures ETN VXX can prove to be a good bet if the volatility levels spike.Notably, the CBOE Volatility Index jumped the most in five weeks on August 8 following President Donald Trump’s incendiary rhetoric on North Korea. VXX gained about 2.8% on August 8, 2017. The S&P 500 fell the most in the month.Overvaluation in Junk Bonds and EM Debt; Look Toward High-Quality BondsHe sees overvaluation in junk bonds and emerging-market debt. He is cutting these positions in DoubleLine funds and targeting higher-quality credits with less sensitivity to rising interest rates. These trades mean staying out of funds like SPDR Bloomberg Barclays High Yield Bond ETF JNK and PowerShares Emerging Markets Sovereign Debt ETF PCY.He expects the Fed to enact its third rate hike of the year in December and in the following quarters if economic data come in favorable. In this light, WisdomTree Barclays U.S. Aggregate Bond Negative Duration Fund AGND, iShares Short Treasury Bond ETF SHV and iShares Floating Rate Bond ETF FLOT could be good choices as these funds offer protection against rising rates (read: 6 Bond ETFs to Play Higher Rates).Flight to SafetyDoubleLine intends to diversify its business and widen focus from the Total Return Bond Fund tothe Core Fixed Income and Shiller Enhanced CAPE. In any case, looking at Shiller PE Ratio is a good indicator for value investing.The metric for the S&P 500 is currently at 80.7% premium to the mean Shiller PE Ratio of 16.77 times. This high number, in the absence of materialization of most of the pro-growth promises made by Trump, calls for a correction in the near term (read: What Does High CAPE Ratio Mean for ETF Investing?).So, investors can take a look atBarclays ETN+ Shiller CAPE ETN CAPE. The product is a senior, unsecured debt security, linked to the performance of the Shiller Barclays CAPE US Core Sector Index. The index looks to provide notional long exposure to the top four relatively undervalued U.S. equity sectors that display relatively strong price momentum.If investors are really scared of impending volatility and willing to forego outstanding returns for safety, they can also consider low volatility products like SPDR Russell 1000 Low Volatility ETF LGLV.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 SPDR-BBC HY BD (JNK): ETF Research Reports IPATH-SP5 VX ST (VXX): ETF Research Reports PRO-ULSH S&P500 (SDS): ETF Research Reports WISDMTR-B USABN (AGND): ETF Research Reports ISHARS-FL RT BD (FLOT): ETF Research Reports SPECIALTY - HEA (SH): ETF Research Reports ISHARS-SH TB (SHV): ETF Research Reports PWRSH-EM SVN DP (PCY): ETF Research Reports DIR-D SP5 BR (SPDN): ETF Research Reports SPDR-R1000 LV (LGLV): ETF Research Reports BARCLY-ETN SC (CAPE): ETF Research Reports To read this article on Zacks.com click here.