If a third world war breaks out, cryptocurrencies could undergo significant changes due to chaos in financial markets and global political instability. Here are the possible scenarios:

1. Increasing demand for decentralized assets: In times of war, governments can impose severe financial restrictions, including freezing bank accounts or capital controls. Cryptocurrencies, particularly Bitcoin, can become a hedge asset for citizens and even corporations due to their independence from traditional financial systems. This can help increase the demand and therefore the price of BTC and other crypto-assets.

2. Increased volatility: Due to market panic and uncertainty, cryptocurrencies can become very volatile. Investors will react quickly to any news, and this can cause both sharp increases and significant drops in prices.

3. Mining problems: War can disrupt supply chains for electricity and equipment. For example, if key mining regions (such as the US or China) are affected, it will affect the hashrate of networks and the stability of blockchains.

4. Regulatory Measures: Governments at war can increase pressure on the crypto industry, arguing that it is to combat terrorist financing or sanctions evasion. This can create significant risks for centralized exchanges and stablecoins.

5. Changing the geopolitical landscape of the crypto industry: Some countries trying to circumvent sanctions (for example, Russia or Iran) may actively use cryptocurrencies for payments, which, in turn, will increase attention to the regulation of crypto assets in the world.

6. Move to Private Coins: People living through military conflicts may prefer anonymous cryptocurrencies like Monero or Zcash to protect their transactions from being tracked.

In general, in the event of a global war, cryptocurrencies can play the role of a financial refuge, but with great risks. The biggest advantage of cryptoassets is their decentralized nature, which becomes especially valuable in times of volatility. However, volatility and regulatory constraints will remain key challenges.