There is no assurance in the crypto market. If you ask me, the only thing there is is that bitcoin has a higher chance of making some big move after halving based on history, but it's not what we will consider as assurance; anything can happen in the market.
Not all altcoins are worth someone's investment; we should be careful when making that choice on which coin or token to invest in. Generalising the diversion to just altcoins without giving it a proper valuation might lead the person to making the wrong choice, which might result in total loss.
Even when Bitcoin experiences a bear run, it tends to have a better market value than Altcoins. I would advise you to look past the previous incident and not regret selling your Bitcoin to acquire Altcoins. The market is inconsistent, and you couldn't have predicted Bitcoin's bull run in Q4 2024.
I wouldn't recommend selling your Altcoins, but rather holding on to them until you see an increase in profit. These are investments, and we know the crypto market is volatile. Prepare your mind for such volatility.
My advice is to take profit from your Altcoins or offline gigs and use it to invest in Bitcoin. Build up your Bitcoin investment while still holding your Altcoins. You never know when the Altcoin market will experience a bull run. We're all speculative about it, and no one has a calendar for when bull runs will happen for Bitcoin or Altcoins.
So, build up your Bitcoin investment while holding your Altcoins. This way, you'll have a win-win situation on both sides when the crpto market experiences a bull run.