Here are some current altcoins that are more than 80% down from their all-time highs and may have upside potential:

1. Filecoin ($FIL )

ATH: $236.84 (April 2021)

Current reduction: ~98%

Why you should consider: Filecoin is a decentralized data storage network that may become popular in the future due to the growing requirements to store large amounts of data on the blockchain.

2. VeChain ($VET )

ATH: $0.28 (April 2021)

Current decline: ~86%

Why Consider: VeChain uses blockchain to improve logistics and supply chain management, and the growth of such sectors could positively impact this project.

3. Cosmos Hub ($ATOM )

ATH: $44.45 (January 2022)

Current decline: ~82%

Why you should consider: Cosmos supports interoperability between different blockchains, and with the growing demand for decentralized technologies, this project could gain new momentum.

These cryptocurrencies still have significant potential to recover from the bull market, although the risks remain high.