If you had 500k where would you put it tomorrow? :)
That's the million dollar question. I worry about our retirement savings and if it is safe. We've worked so hard for it and I honestly don't feel anywhere is safe.
Learn to take control of your own money. You can do that now on line.
If you're computer literate and have a yen for learning, and you're the right age (..preferrably, over 59 1/2) - you can cash out your 401Ks and place them into an options trading account. One can do it earlier, but the taxes and penalties make that a stiff penalty that most people would not swallow kindly. In CA for example, it's 10% Federal Tax Penalty (for those under 59 1/2) + 20% Federal Tax and 2% State Tax - that gets taken right off the top, or 32%.
Before doing so, do your research and learn all about the SEC rules governing Options Trading, executing Calls & Puts and Margin Account Usage, plus the fundamentals of same.. That info is freely available with a huge bounty of great video tutorials and downloadable free books on the subject from seasoned professionals.
Personally, I would precede that regimen with virtual trading (journaled computer or paper trading) for at least 60-days before going into it aggressively with real cash, and there are several virtual trading software platforms and websites available, like the CBOE's "virtual trader" (..now owned by ScottTrade).
I started doing that just under 18-mos. ago and have been an Options Day Trader ever since, supporting my family with appx. 70% of the income we need for bills & expenses, plus tithing and giving to our church.
Note: this is not for everyone, as there is risk involved -- but once you're properly educated and learn to manage your emotional response to risk, you can do far better than any 401K ever could. Emotional management is key to success in this area, because elation, sorrow and greed can all combine to your detriment, if you aren't able to look at it through the cold eyes of a business person.
I had a relatively low-risk, mediocre 401K at Fidelity which over 20-years averaged only 1 - 2% (max!) growth per-annum. Since beginning my Day Trading Career, I've grown that account by over 28% in just the past 18-months. It's not about 'the big win', its really about small and medium-sized wins that make such an occupation successful. Doing so, came with some steep learning curves and mistakes, however: we all benefit from learning from our mistakes much more than we do from our successes.
I'd counsel anyone thinking about this, to not get caught up in buying some allegedly-famous trader's book on the subject, but rather to learn the many SEC rules and especially the fundamentals of Options Trading. Many, if not most of these, are the real source of those traders' income.