On December 16, 2025, Solana announced a partnership with Project Eleven to develop and test quantum-resistant digital signatures on a Solana testnet. The initiative includes a full quantum-readiness assessment of wallets, validators, and transaction flows. Solana's founder Anatoly Yakovenko has previously cited a 50% probability of quantum attacks against Bitcoin in the coming years, while current threats remain theoretical.

According to data from Pipe, Solana's network absorbed a distributed denial-of-service attack peaking around 6 terabits per second this week without downtime or notable fee spikes, a performance later confirmed by co-founders Anatoly Yakovenko and Raj Gokal. The event coincides with a more than 35% drop in active validators in 2025 and growing concentration of stake among large infrastructure providers, even as Solana processes roughly $1.6 trillion in annual trading volume and supports about $15 billion in stablecoins.

Aave founder Stani Kulechov stated that a four-year SEC investigation into the Aave protocol has concluded without enforcement action, signaling a notable regulatory development for DeFi. Following the news, the AAVE token climbed 2.28% to $187.45 on December 16, 2025, with a market capitalization of $2.87 billion despite a weekly decline.

On December 16, 2025, a large holder exited six AI agent tokens, reducing a $23 million position to $2.58 million and realizing a $20.43 million (−88.77%) loss. The drawdown included steep declines across FAI, AIXBT, BOTTO, POLY, NFTXBT, and MAICRO. The broader AI token sector has remained weak despite a brief daily uptick in market cap.

On 16 December 2025, the UK High Court refused to reopen a major lawsuit linked to Bitcoin Satoshi's Vision that sought billions in damages based on hypothetical price outcomes. The ruling reinforces earlier UK case law that prioritizes investor responsibility and market risk over claims tied to "missed upside" or alternative market histories, narrowing the scope for future crypto litigation over delisting decisions.

PIPPIN jumped to a fresh all‑time high on December 16 following a sharp squeeze in derivatives. Shorts dominated open interest, while on‑chain whales executed coordinated spot orders on Raydium and PumpSwap. The team made no new announcements during the move.

On December 16, Shiba Inu's SHIB token traded around $0.00000790 after dropping 3.73% in the last day. The price recently failed to hold above the $0.00000799 resistance and is now hovering closer to support, with bears watching the $0.00000755 level and a possible move toward the $0.0000070 zone if pressure persists.

In December 2025, analyst JD highlights XRP’s retest of the 21-month EMA, echoing a similar setup seen before its January 2018 all-time high. JD suggests that if XRP can hold this key trendline over the next 20 days, it could open the door to a fresh record high in Q1 2026, though a sharp correction could also follow. The pattern underscores how crucial this EMA level is for XRP’s potential upside and downside in 2026.