A survey of 400 professional European investors suggests exchange traded funds (ETFs) are being used more and more as a long-term investment tool, rather than for short term trades.

Vanguard, which carried out the study between January and March, claimed the European ETF industry at was worth $726 billion in December 2018, having almost doubled in value over the preceding five years.

Nearly half (47 percent) of those surveyed used ETFs for core buy and hold investing, while only a quarter used them primarily for tactical investing.

ETFs are lauded for providing cheap access to a potentially balanced and divers...