Investing basics
How Not to Pick a Stock
The biggest investing mistakes beginners make and how to avoid them
Most people don't lose money investing because they picked a terrible company.
They lose money because they bought for the wrong reasons.
That's an important difference.
The stock market has a habit of making ordinary companies look extraordinary during good times, and brilliant companies look terrible during bad times. If you learn to recognise the traps that catch most investors, you'll already be ahead of the crowd.
Key idea: Successful investing is often about avoiding mistakes rather than finding perfect companies.
A crossroads with signposts labelled "Hype" and "Research", with an investor choosing the research path.
Mistake #1: Buying because everyone else is
Imagine you're at a barbecue.
Someone says:
"You need to buy this stock. It's doubled already."
By Monday morning you've bought it.
You have no idea:
- what the company actually does
- whether it makes money
- whether it's expensive
- why it went up in the first place.
You've simply copied someone else's homework.
Experienced investors don't ask:
"Who's buying?"
They ask:
"What am I actually buying?"
Mistake #2: Falling in love with the product
This catches almost everyone.
You love your Tesla.
You wear Nike trainers.
You buy everything from Amazon.
That doesn't automatically make the shares a good investment.
Sometimes the world's best companies become terrible investments simply because investors have already pushed the share price too high.
Robbie Burns often reminds readers that great companies aren't always great shares.
The price you pay still matters.
Mistake #3: Ignoring valuation
Suppose somebody offered to sell you a local café.
It makes £100,000 profit every year.
If they asked:
- £400,000...
- £600,000...
- £1 million...
...you'd probably think differently about the deal.
Shares work exactly the same way.
You're buying future profits.
Pay too much and even a wonderful business can disappoint investors.
Sleep Score principle
Always ask:
"How many years of today's profit am I paying for?"
The higher the number, the more future success is already priced in.
Mistake #4: Chasing yesterday's winners
One of the hardest lessons in investing:
Yesterday's best-performing stock is rarely tomorrow's best investment.
People naturally chase success.
Unfortunately, markets know this.
By the time something is on the front page of the news, much of the excitement is often already reflected in the share price.
Peter Lynch preferred finding businesses before everybody else noticed them.
Mistake #5: Ignoring debt
Two companies both earn:
£50 million profit.
One owes nothing.
The other owes £600 million.
Those businesses are not equally strong.
Debt isn't automatically bad.
But too much debt gives companies fewer options when things get difficult.
That's why experienced investors always check whether profits comfortably cover borrowing.
Mistake #6: Listening to exciting CEOs
Some executives are brilliant presenters.
Some are brilliant business leaders.
The two aren't always the same.
Warren Buffett has often preferred managers who speak plainly, admit mistakes and focus on long-term results rather than exciting headlines.
Ask yourself:
- Do they admit problems?
- Do they blame everyone else?
- Have they delivered what they promised?
Actions matter more than speeches.
Mistake #7: Looking only at the share price
A falling share price doesn't necessarily mean something is wrong.
A rising share price doesn't necessarily mean everything is right.
Markets can become emotional.
That's why experienced investors spend more time reading annual reports than daily share price charts.
Numbers tell you what happened.
Management often tells you what's coming next.
Mistake #8: Believing investing should be exciting
The best investments are often...
...a little boring.
Companies quietly increasing profits.
Growing cash generation.
Managing debt sensibly.
Looking after shareholders.
These businesses rarely make headlines.
But over ten or twenty years they often produce outstanding returns.
Robbie Burns frequently points out that investing shouldn't feel like gambling.
If your portfolio gives you constant excitement, something may already be wrong.
A simple checklist before buying any share
Before investing, ask yourself these questions:
| Question | Why it matters |
|---|---|
| Do I understand what this company does? | Never invest blindly. |
| Is it making consistent profits? | Profits fund future growth. |
| Am I paying a sensible price? | Great companies can still be overpriced. |
| Is debt manageable? | Too much borrowing increases risk. |
| Does management sound honest? | Trustworthy leaders usually make better long-term decisions. |
| Could I happily own this for five years? | Long-term thinking reduces costly mistakes. |
How the Sleep Score helps
DeepSleepInvest isn't trying to predict tomorrow's share price.
Instead, it asks the same kinds of questions experienced investors have been asking for decades.
It looks at factors such as:
- sensible valuation
- manageable debt
- growing profits
- management confidence
- warning signs
- shareholder returns
None of these guarantee success.
Together, however, they help paint a clearer picture of the business you're actually buying.
Imagine two companies both rise 20% this year.
One has growing profits, little debt and honest management.
The other has falling profits, rising borrowing and increasingly cautious reports.
Both made the same return.
Which one would you feel happier holding for the next five years?
Final thoughts
The biggest investing mistakes rarely come from a lack of intelligence.
They usually come from emotion.
Fear.
Greed.
FOMO.
Impatience.
The goal isn't to find perfect companies.
It's to avoid buying poor businesses for the wrong reasons.
Do that consistently, and you'll already be investing more like Buffett, Lynch and Burns than most people in the market.
Key idea: Investing is less about finding the next superstar and more about avoiding the obvious mistakes that quietly destroy long-term returns.