Much like hedge funds diversify their portfolios, art collectors also maintain diverse collections to mitigate the risks the of the market. This is an old practice, but there has been a marked rise in cross collecting since the start of the century. In museums, recent exhibitions have been using the juxtapositions of various art movements, media, etc. to engage public interest in a similar way.
Since the start of the new millennium, there has been an increase in cross-collecting (sometimes called 'cross-over buying'). This might seem like a recent phenomenon according to what we witness in both public sector exhibitions, commercial galleries and their art fair stands. However, the practice has been around since antiquity.