Stocks have been on a wild ride throughout 2016, leaving many investors unsure about the stability of the seven-year bull market. Investors in the United States are finally seeing the majority of stocks rebound back into positive territory for the year, but the rebound has not benefited all market-cap classes equally. As of April 2016, large-cap stocks in the S&P 500 Index gained 1.98% year-to-date (YTD) and small-cap stocks in the S&P 600 Index climbed 3.19% YTD. Mid-cap stocks appear to be just what investors are looking for right now, after the S&P 400 Mid-Cap Index climbed nearly 5% YTD.

The bulls and bears tangled to start off 2016; however, it appears the bull has prevailed for now. While the market is always facing periods of bullish and bearish strengths, the long-term trend has continued to be in bullish control since the Great Recession and its lengthy bear market. Understanding the signs and warnings that come with a changing bull/bear market cycle can help investors protect their portfolios from devastating losses.

As mid-cap stocks continue to be the hotspot within the U.S. market, bullish positions are likely to continue to see gains. Whether the mid-cap rally will continue or if bearish influence will push the stocks lower, here are four mid-cap ETFs to consider for returns during a bull or bear market.

Bullish ETF: WisdomTree MidCap Dividend ETF

Investors looking for U.S. mid-cap exposure that is moderately actively managed and seeks out top dividend payers could turn to the WisdomTree MidCap Dividend ETF (NYSEARCA: DON). DON seeks to provide returns closely relating to the performance of its benchmark index, the WisdomTree MidCap Dividend Index.

DON would make a good selection during periods of bullish strength because the ETF provides exposure to strong U.S. mid-cap stocks that also pay dividends. Bull markets foster growth in capital gains, and DON also pays an above-average dividend yield compared to other mid-cap ETFs. As of April 2016, WisdomTree MidCap Dividend ETF had an expense ratio of 0.38%, a yield of 2.37% and a five-star rating from Morningstar Investment Research.

Bullish ETF: iShares Core S&P Mid-Cap ETF

Investors who want a more passive and broad approach to their U.S. mid-cap exposure could look at the iShares Core S&P Mid-Cap ETF (NYSEARCA: IJH). IJH is a passive index fund that seeks to closely replicate the underlying performance of the S&P 400 Index.

IJH is a worthy consideration during bull markets because it provides investors with a basket of around 400 mid-cap stocks that make up the S&P 400 Index. This broad diversification and index investing can lead to strong gains during bull markets. As of April 2016, IJH had an expense ratio of 0.12%, a yield of 1.54% and a four-star rating from Morningstar.

Bearish ETF: ProShares Short MidCap400 ETF

Turning to mid-cap ETFs that thrive during bear markets, one of the first that comes up is the ProShares Short MidCap400 ETF (NYSEARCA: MYY). This non-leveraged ETF seeks returns that are equivalent to the opposite of the S&P 400 Index’s daily performance.

While stocks generally turn higher over longer periods of time, bear ETFs, such as MYY, should be used sparingly and with a trading mindsets rather than as long-term, buy and hold investments. With that being said, MYY is a worthwhile investment vehicle to capture gains when U.S. mid-cap stocks enter a bear market. As of April 2016, the short S&P 400 ETF had an expense ratio of 0.95%, no yield and no Morningstar rating.

Bearish ETF: ProShares UltraShort MidCap400 ETF

Closely related to MYY, the ProShares UltraShort MidCap400 ETF (NYSEARCA: MZZ) offers investors the ability to short the S&P 400 Index using leverage. MZZ is designed to provide returns that are equivalent to twice the inverse of the daily performance of the S&P 400 Index.

MZZ is an ideal ETF for experienced and aggressive investors who want to either hedge portfolio losses during a bear market, or to use as a short-term speculation tool. Strategic use of the ETF would provide the best returns when the markets are encased in fear, uncertainty and steep stock losses. As of April 2016, MZZ had an expense ratio of 0.95%, no yield and no rating from Morningstar.