Investing rules of thumb are usually misleading, but there are time-tested ones that can help you succeed with investing. It’s also important to keep important changes to the market in mind as you invest.

I’d say you are in for a hard time if you try to apply the investing rules of thumb you picked up in the 2010s to the future. Changes in interest rates, foreign exchange and deficit spending may scuttle a lot of investment plans and predictions.

When I say “predictions,” I’m using a wide and loose definition. It includes casual guesswork based on longstanding investor rules-of-thumbs. It also includes the 100-page-plus reports that the financial industry routinely produces when launching an IPO.

Here are some issues you need to keep in mind to stay on the winning side of investments.

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The great monetary experiment. In the past century, the world’s great powers have shifted from a gold-linked monetary system to a system based on fiat money—paper or electronic money with no intrinsic backing. Fiat money only works as a medium of exchange/store of value because it has the backing of government decrees or fiats.

This long-term multinational experiment could struggle on for decades to come—or it could come unglued abruptly. That’s why we invest a portion of our clients’ funds in gold stocks. We see golds as buys on their own fundamental merits. A revival of inflation could spur widespread investor interest in gold. If that happens, gold prices could rise much faster than the costs of mining gold. This would multiply the value of gold stock prices.

The downside of alternative investments. These investments cover a huge variety. In fact, anything that doesn’t fit in the traditional stock & bond grouping could probably pass as an “alternative investment” these days.

Judging by how many investment dealers now deal in “alternative investments,” they may get more sales promotion than traditional stocks and bonds. That’s not a surprise. After all, there’s more potential profit in selling alternative investments than the traditional stuff.

Alternative investments generally don’t trade in open, competitive markets. Instead, the dealers set prices. Worse, vendors of alternative investments are often in a conflict-of-interest position against their clients. Clients are generally unaware of it.

Stalking the elusive unicorn. The biggest alternative investment market these days is in VC (venture capital: funding of start-up companies), and PE (private equity: trading and investing in existing companies that do not trade publicly).

Many of those active in venture capital and private equity have amassed great fortunes. I suspect that those who set up and sell VC and PE deals made most of the money. After all, the dealmakers write up the terms of the deals. Clients just put up the money.

Be wary of bitcoin-bubble risk. In the dozen or so years since it came into the world, bitcoin and its fellow cryptocurrencies (pseudo-currencies seems more accurate) have led to the creation of two trillion dollars’ worth of value. Only a tiny, tiny portion of that total gets traded on the average day, however.

This high volatility-minimal trading combo leaves today’s bitcoin bubble extraordinarily unstable. It’s a bubble unto itself, but its influence spreads out to other obscure corners of the speculative world.

My guess is that when the bitcoin bubble pops, it will have a devastating impact on the value of SPACs, recent new issues, venture capital/private equity financing, short-selling compacts and other speculative ventures and activities. Fortunately, the end of the bitcoin bubble is likely to have little permanent impact on well-established companies with a history of earnings and dividends.

If you’re tempted to indulge in today’s high-risk investment innovations, we advise you to do so only with money you can afford to lose.

Bonus tip: Investing rules of thumbs you can use:

The sell-half rule can be helpful to aggressive investors

Selling half of hot stocks that surge helps you guard your profits. But in general, apply this rule only to more aggressive stocks, and not to the well-established stocks that may surprise you by going a lot higher in the long run.

Selling half after a stock’s price doubles makes sense in a high-risk investment such as a penny mine. That way, you get back your initial stake. This can give you a clearer perspective on what to do with the other half of your investment. If you are too slow to sell speculative stuff, after all, your profits and even your principal can evaporate all too quickly.

However, as mentioned, it’s a mistake to apply this rule to your best holdings that are not high-risk investments. To succeed as an investor, you need to hold on to your best picks for lengthy periods. If you’re too quick to sell, you’ll never hold a stock that vastly outperforms the market, and you need a few of those to offset the inevitable disappointments.

Use our three-part Successful Investor approach as the basis for picking stocks—not rules of thumb

1. Hold mostly high-quality, dividend-paying stocks.
2. Spread your money out across most if not all of the five main economic sectors: Manufacturing & Industry, Resources & Commodities, Consumer, Finance and Utilities.
3. Downplay or stay out of stocks in the broker/media limelight.

Do you pay attention to investing rules of thumb, or do you focus on financial data to make your decisions?

Do you have any rules of thumb that you follow or use to guide your investment decisions?