Who said HODL for the first time?

December 18, 2013

This is how Hodl started, in a Bitcointalk forum post, by user GameKyuubi, he said why he was still "hodling" (unsold) in his post, "I AM HODLING", he already knew there was a misspelling, but decided that hodling was the best definition.

Since then, HODL has been used countless times to comment that in a price drop, don't sell, hold Hodl, or that the least risky way to own Bitcoin is with Hodl.

Bitcoin UTXO Age Distribution

https://hodlwave.com/

UTXO is the output of the unspent transaction (TX).

HODL 

Meaning of UTXO, unspent transaction output (TX) Each on-chain bitcoin transaction sends bitcoin to one or more addresses.
UTXO data track the last time the coins were moved, the increase in the cumulative age of UTXO represents a larger market share.
The balance of a bitcoin wallet is actually the sum of the UTXOs controlled by the wallet's private keys.