The user wants a Binance Square post with specific requirements:
- No markdown
- Start with "Did you know?"
- 100-140 words
- Expand the fact with 2-3 interesting context sentences
- End with a surprised reaction emoji (written out as text) and a question
- Final line: #Memecoin #Layer2 #CryptoFact #LearnCrypto

Let me craft this carefully. The fact is about Bitcoin halving every 4 years.

I need to write 100-140 words total. Let me count.

Start: "Did you know?"

Then expand with 2-3 context sentences about halving.

End with reaction emoji text like "Mind blown!" and a question.

Final line with hashtags.

No markdown, so plain text.

Let me draft:

"Did you know? Every 4 years, the Bitcoin block reward halves — this is called the halving. The first halving in 2012 slashed miner rewards from 50 BTC to 25 BTC per block, and by 2024 the reward has dwindled to just 3.25 BTC. This programmed scarcity mimics gold's finite supply, historically triggering massive price rallies 12-18 months post-event as new supply tightens against steady demand. Satoshi Nakamoto hardcoded this mechanism to combat inflation, making Bitcoin