The fund tracks the STOXX International Equity Factor Index, and it gains exposure to five factors (momentum, quality, value, low volatility and size) in developed-market stocks outside the US through a rules-based process.

It suits long-term investors who want to add overseas developed-market stocks to a portfolio with a heavy US weighting, and who prefer to blend several factors rather than lean on a single one.

It is a passively managed (index-tracking) ETF run by BlackRock's iShares.

The index does not simply hold individual stocks by market-cap weight. It combines them so that scores on all five factors are raised at the same time. Most of the fund's assets go into holdings with the same economic characteristics as the index constituents, and the large number of holdings broadly diversifies single-company risk.

• A structure that captures five factors in one product rather than a single factor
• A relatively low cost burden among overseas developed-market factor products
• Because the process is rules-based, concentration in particular countries or sectors is controlled at the index level

Assets under management (AUM) stand at $3.7B, and the total expense ratio is 0.16% per year.

Within the same overseas developed-market equity category, the FNDF ETF and GSIE ETF differ in how they define factors and calculate weights. Trading volume is thinner than in very large overseas core ETFs, so it is worth checking the bid-ask spread.

The fund follows the broad movement of overseas developed-market stocks, but thanks to its low-volatility and quality exposure, it tends to rise more gently than the index in sharp rallies and fall less in corrections. Performance varies with the factor cycle.

Demand to rebalance portfolios that have become heavily concentrated in the US is the backdrop for fund flows into overseas equity ETFs. When the direction of the dollar and the earnings of European and Japanese companies shift, inflows and outflows in this category move together.

Its strengths are a low expense ratio and diversification across five factors, while its weaknesses are periods of factor underperformance, thin trading volume and currency exposure.

The FNDF ETF and GSIE ETF shown in the table also cover overseas developed-market stocks, but they select holdings through fundamental weighting and an active beta approach, respectively. Funds such as IGF and GNR invest in infrastructure and natural resources, so they cannot be viewed on the same footing, and they serve as references only in terms of expense ratio and fund size. For plain market-cap-weighted overseas core exposure, IEFA, VEA and EFA are substitutes. To hold low volatility on its own, you can consider EFAV, and to extend into emerging markets, ACWX is another option.

Here are the points to check before buying INTF. Because factor products do not track the index one for one, it helps to understand in advance which market phases they lag in.

There are periodic stretches when the factor mix moves differently from the market index. When currency and regional economic variables overlap with this, the volatility you experience differs from holding US stocks alone.

It suits long-term investors who want to reduce their US concentration and hold overseas developed-market stocks at a low cost. If you want plain market-cap exposure, compare it with IEFA, VEA and similar funds before choosing.