Help determine bonus check best tax strategy

[Redgy Saint-Germain]

Hey guys, 

I am asking as an investor some suggestions and I understand this is in no way "legal advice". Here is the situation 

I will receive a bonus check from my W-2 job and for numbers sake we`re gonna say its 50k, now according to the IRS my employer will withhold 25% in other words 12500$ for tax purposes. Now we can all agree this is quite a bit of money that can be invested in a deal. I can take the hit now, pay the 12.5k and get a refund next year or I can try to figure out the best strategy to invest that money in a deal or two this year. I have thought about putting the whole thing into my 401k and take a loan to invest but for 2018 your max 401k contribution is 18500$. 

This is where I need some suggestions :)  feel free to comment.