This is going to sound harsh, but that bad investment advice for most people. US Bonds and Cash appreciate less than inflation, so you're actually losing money. The same is true for gold, which has historically underperformed vs. S&P500 (for example) by thousands of percent (http://www.longtermtrends.net/stocks-vs-gold-comparison/). Meanwhile the stock market has more than doubled in the past 10 years. 25% is almost definitely not enough equity exposure unless you are in your golden years. If you're investing for the long term (which you should be), it is much better to use a simple index funds or Robo-manager which will buy a variety of index funds with broad exposure according to modern portfolio theory.
If you put all of your money into the S&P500 only at the absolute, single worst possible day (the market top on May 16th, 2008 at $1,425) you would still be up about 100% today, 10 years later at $2,779 (So about 2X, just checked).
If you put money in "after the plummet," as you suggest, which is the best case scenario, (buying at the low of $735 in January of 2009) would put you up approximately 300% (4X).
The average investor would get somewhere between these two just by ignoring the market and investing biweekly.
I'm not even advising to go 100% for the S&P500 Index Funds. However that's an infinitely better idea than a portfolio that is 75% of Gold (Dumb), T Bills + Cash (Losing money everyday), and Bonds (Which are paying at near-historic lows). It's just bad advice.