Stocking up is probably the best thing to do during this time that the market is in sideways because you have a discounted price for all the bircoin out there in the market. Plus it's a great filter for people who don't deserve to get a big profit because these times can make someone easily panic over the fact that the prices are going wild.
It really really does depend on what you are doing though. If you are holding or trading super long term then for sure, sideways is buying time, but not too much too or you got nothing left when the real dip happens. On the other hand, if you are a short termer then you keep wanting to make money from volatility even during sideways market periods.
Stick to the plan, if Plan A never works then we have to proceed with Plan B or else, we have to set for another Plan as the situation is also changing. Either be a short-term or Long-term trade, it also depends on the market trend. We need to be flexible as we never know the trend of the market but more possible it is certainly moving up and down, and as a trader, we have to analyze it otherwise our trade will end up in losses and failure.