In these situations, arbitrageurs receive margin calls, after which they would most likely be forced to liquidate part of the position at a highly unfavorable moment and suffer a loss.
Individual investors are not able to take advantage of these arbitrage opportunities but arbitrageurs can, due to better information and greater access to capital.
However, due to margin requirements, even arbitrageurs may potentially face financial constraints and may not be able to completely eliminate the arbitrage opportunities.
In particular, the equity option embedded in the convertible bond may be a source of cheap volatility, which convertible arbitrageurs can then exploit.