This is a good decision because people are expecting bitcoin to fall by next year, although we do not know yet if it will be true not or but the best time to buy bitcoin is when the price falls significantly during bear market and hold the coin for a long period of time. When the price is already high the way it is now, I do not advise people to invest yet.
Yes it's an utmost decision of Op getting to sell his AltCoins for bitcoin but I'll advice a diversification of investment since the crypto markets varies. So he can always take part of the beneficiaries at the market rises.
While Op might be ready to key in to his decision now, I'll suggest he buy some now and hope to Dca at the market fall hopefully after the bull market is over. If we also look at investors speculations and our individual expectations, bitcoin might reach $200,000 within this bull event though we ain't sure if it'll and when it'll but in the sense that investors buying now will not loose their funds as far as bitcoin is reliable and with institutional investors buying more to their holdings, bitcoin will sustain valuable ratio. And if paraventurely we see the $200,000 and Op is invested at the price of the current Ath of $111,000, we'd be having over 80% increase which if Op invests now, he'd still be a profit.
Maybe he can sell and begin buying from the bottom price again when the market drops somewhere after the market Spikes.