Small-caps also provide greater diversification benefits. For instance, smaller company stocks are quicker to react to market rebounds, usually outperforming larger companies during the initial stages of growth. However, small-caps are also more likely to experience greater volatility during down markets.

The small-cap segment is also more focused on the domestic economy, which makes them less affected by global macroeconomic shocks.

As a one-stop-shop global market investment, the SPDR MSCI ACWI IMI ETF (NYSEArca: ACIM), which tracks the MSCI ACWI IMI, can help investors gain exposure to the global markets through a single ETF holding. The underlying Index is a free float- adjusted market capitalization-weighted index that captures up to 99% of the developed and emerging investable market universe.

Alternatively, if an investor already has international market exposure but just lacks foreign small-cap holdings, there are also a number of focused small-cap international ETFs as well.

For instance, the Vanguard FTSE All-World ex-US Small-Cap ETF (NYSEArca: VSS) follows the FTSE Global Small Cap ex US Index and provides an easy way to gain broad exposure across developed and emerging market companies outside of the U.S.

The WisdomTree International SmallCap Dividend Fund (NYSEArca: DLS) is another option, except this ETF specifically screens for dividend-paying small-caps to help investors satisfy demand for income, along with growth potential.

Additionally, the Schwab Fundamental International Small Company ETF (NYSEArca: FNDC) takes companies with weights below 87.5% of the Russell Developed ex-U.S. Index and applies a fundamental indexing methodology that weights holdings based on adjusted sales, operating cash flow, and dividends plus buyback.