anyone know why USDC volumes on Solana at the end of 2021 went insane? it's all bot activity but i can't identify what kind of bot activity / why it happened. 

From the Visa onchain stablecoin project:

anyone know why USDC volumes on Solana at the end of 2021 went insane? it's all bot activity but i can't identify what kind of bot activity / why it happened. 

From the Visa onchain stablecoin project: https://visaonchainanalytics.com/transactions

Not sure if this is where you're looking for. From the Adjusted Transaction Methodology:
Other (Adjusted): Volume from addresses that are unlabeled and have done less than 1,000 transactions and $10m in transaction volume over any 30-day rolling period.
Other (Unadjusted): Unlabeled addresses that exceed our threshold of 1,000 monthly transactions or $10m monthly volume. Meant to exclude unlabeled bots and high frequency traders not captured by current labeling.

So my interpretation: Other (Adjusted) seems to be retail buying the top, and Other (Unadjusted) seems to be mainly trading imo (also because of the timing). I can't tell you with 100% certainty, but it seems likely to me.

not a dude. crypto is such a weird and fun place.