Avalanche’s Helicon upgrade is scheduled to activate on Mainnet on Sept. 22 at 15:00 UTC, reducing the minimum Primary Network validation period from 336 hours to 48 hours. Validators must install AvalancheGo v1.15.0 to remain compatible. Eligible validators will be able to auto-renew their own stake cycles, choose how much reward to compound into the next cycle, and update that setting for a future cycle. Delegations will not auto-renew and must fit within one validator cycle. New validation periods starting after activation will require at least 90% uptime to earn rewards, up from 80%; the change is not retroactive. Rewards remain all or nothing, and falling below the applicable threshold forfeits the period’s reward without slashing principal. For auto-renewing validators, a failed cycle also prevents continuation, although principal and rewards from earlier cycles are returned. Helicon will also begin a 90-day linear reduction in the minimum consumption rate from 10% to 7.5%, while leaving the one-year maximum rate unchanged. Avalanche modeling estimates a roughly 1.3% reduction in the shortest-duration annualized reward rate, a 0.5% to 1% decline in annual AVAX inflation, and an approximately two-month increase in stake-weighted average duration. Actual yields will vary with AVAX supply, duration and compounding choices.