Nice article. However, it is not a glitch. There was a chain re-organization in the Bitcoin blockchain. This is a common occurrence that is part of Bitcoin's normal operation. It is a result of decentralized consensus under Proof-of-Work. All PoW chains do this. It's about confirmations too and it is much more elaborate than trying to explain it here

This is not investment advice - I agree with what you said: "If you understand Bitcoin, then you’re in it for the long haul." But you need to understand it.