I think perhaps the question in my mind is more about the tax implications... I don't know exactly how it would work or the loopholes as I'm inexperienced myself, but I'll take a stab at it. Professionals out there PLEASE correct me as this is just conjecture on my part.
I'll base the following on the assumption they are a year old and the value from this time last year (750ish) to now (1000ish) x10 stocks is now at $10,000.
If you sell you'll owe taxes on the gains (unless you had them over a year and are currently in the 15% tax bracket...[0 capital gains tax]). If you had them for only a year, value would have increased from 750 a share to 1000 a share (roughly). Capital gains at current value would be about $2500. (250/share x10 shares) for a tax liability of $375 (2500x15%). If you are in the 20% tax bracket, the additional 5k you can put in your 401k saves you $1000 in taxes. By selling you pay 375-400 in capital gains taxes vs 1000 in ordinary income tax. Difference of $600 or so, not counting state tax or any effects this may have on ACA subsidies and the like. You would also be sitting on the other $3500 from your stock sale ($10,000- $5000 401k - $1500 taxes) which you could use to help fund your IRA contributions for the year. If you put it in a Roth IRA you could later use it penalty free towards your 1st time home buyer purchase. (Roth account must be 5 years old or older for this perk).
The tax code makes my head spin, but I believe the above to all be true. You should do your own due diligence or consult an actual tax professional for real advice, as I'm an internet nobody, but these are some ideas to think about.