Be smart in your allocation
All mid caps are not equal. Investors are known to lose money by investing wrongly. However, if you are labouring under the notion that all are speculative bets, you are wrong. Some mid-cap stocks display some impressive traits that an equity investor should look at - market leader, good balance sheet, competitive advantage, great management skills and entrepreneurship, ability to manage scale, and so on and so forth.
As an investor, it would be wise to have some portion of your portfolio assigned to mid caps. How much will purely depend on your risk-taking capability. As mentioned earlier, mid caps are inherently a risky investment avenue and require investors to have the stomach to digest the higher volatility that comes along with the turf. If volatility gives you sleepless nights, then maybe you should bypass this investment option. If you are not fazed too much by the ups and downs, then the next step would be deciding how much of your equity allocation should be directed towards mid caps.