Passive equity portfolios continue to gain popularity. But a small group of outperforming stocks have driven most of the gains in recent years. Concentration risk could become a big burden if the favorable environment for these companies sours.

Value investing has always been about challenging the consensus—but never more so than today. After several tough years, we're seeing signs of a value recovery brewing. Yet fresh approaches are needed to capture the potential in today's complex markets.

As trade tensions escalate, investors are flocking to stocks of smaller US companies, which rely less on foreign sales than their large-cap peers. But in some industries, tariffs could affect smaller companies in unexpected ways.

As concerns about inflation spread, it's time to gauge how different types of stocks will respond. Smaller companies in niche markets may be better positioned to cope with rising prices-especially in consolidating industries.