Greek crypto tax, Nigerian stablecoin ban: how well do you know this week's crypto news?

Seven questions from this week's crypto and fintech news: Greek tax rules, Nigeria's stablecoin rules, a South Korean exchange halt and Ethereum's next upgrade.

1. What tax rate will Greece apply from 2027 to profits from selling crypto assets?
2. Up to what annual net profit does the Greek crypto tax stay at zero?
3. Under the Greek rules, which transaction does NOT by itself create taxable gains?
4. What type of stablecoins did Nigeria's central bank ban in its new rules?
5. What minimum buffer above full backing must Nigerian stablecoin issuers hold?
6. What led South Korea's GOPAX exchange to suspend trading?
7. Until how many smart-contract invariant risks are resolved was Ethereum's Glamsterdam fork on the Hoodi testnet postponed?