This is a key advantage of investment trusts when investing in sectors such as this. Investment trusts don’t run the same risk of having to sell assets in a hurry because investors are suddenly pulling their money out. Core choices in the investment trusts sectorSo what are some of the core options in the sector? The largest small- and mid-cap trust, with £2.2 billion in assets under management (including gearing of 14% at present), is Mercantile Investment Trust (LSE: MRC), managed by JPMorgan. Investment trusts for focused portfoliosOdyssean Investment Trust (LSE: OIT) and Rockwood Strategic (LSE: RKW) are worth considering for focused portfolios.