Is Coast FIRE risky if I stop contributing decades before retirement?
Coast FIRE carries a specific risk: you are betting that market compounding alone will grow your current balance into your full number, so a long stretch of below-average returns could leave you short. Since you have stopped adding money, you lose the powerful effect of buying more shares during downturns.
Manage this by using a conservative return assumption when you set your Coast number, revisiting the math every year or two, and being ready to resume contributions if growth lags. Keep an appropriate stock allocation, because too little equity may not deliver the growth Coast FIRE depends on. Many people treat Coast as flexible rather than final, coasting when life demands it and topping up when they can. Recheck your assumptions periodically with wealthserene.com/tools/fire-calculator.