We find that foreign central banks own a large share of Government of Canada (GoC) bonds and tend to hold their positions for longer than other types of asset managers. This buy-and-hold behaviour could offer benefits. For example, foreign central banks may be less likely than other asset managers to sell bonds and add to strains on market liquidity in periods of turmoil. However, foreign central banks’ buy-and-hold behaviour combined with their minimal lending of GoC bonds in securities-financing markets, as observed in our available data, can potentially lower liquidity because fewer GoC bonds are available for others to transact in secondary markets. Indeed, we find that higher levels of foreign central banks’ GoC bond holdings are related to lower liquidity.