River research analysis states that the loss of Bitcoin due to poor self-custody management has exceeded incidents related to exchanges, totaling about 1.6 million BTC (worth over $15 billion), higher than the losses caused by Mt. Gox hacking and FTX bankruptcy which amounted to 1.2 million BTC (over $11 billion).
The study uses a probability model to analyze wallet activity and found that wallets not used for a long period (10 years or more) account for the majority of losses, while short-term inactive wallets have a lower probability of loss.