Bitcoin halving occurs when every 210,000 blocks - the total number of bitcoins that miners can get as a reward is divided by two. Nowadays it is extremely hard to get Bitcoins by mining because of special made ASIC miners and increased difficulty. This makes it easy for hooks to only execute in special cases. Best Cryptocurrency Exchange: What Does It Mean for Us? It shouldn’t mean (and hopefully doesn’t mean) that your BTC are insecure right now, but there is an increased chance that your BTC aren’t secure at some point in the (far) future when this particular cryptographic standard is weakened. Update: Trezor has removed BCH for now, https://youtu.be/vLCo6XUHiCQ due to a bug in their Bitcoin Cash backend server. Update: This issue is now fixed. His version of the Existential Threat of Earth had now boiled down to 1,000 people.