Make sure you have a plan going into this run

and if you have one, stick to it.

I know this is much easier said than done - I'll be the first to admit I will probably get caught up in this next bull run (should it prove to be one) - but if you set yourselves 'investing rules' and actually abide by them, you'll likely have fewer regrets.

If you've told yourself you're a DCA investor, stick to that strategy if you think it's best; if you've told yourself you are going to take profits at a certain point, again abide by the rules you've set yourself; if you're a long term investor and don't intend to sell for ten years, don't get faked out by sudden fluctuations...and so on and so on.

Life is effectively about minimising your regrets; do what lets you sleep at night and you'll have done the right thing. Good luck out there, this is going to be interesting regardless!