Common mistakes new investors make

The errors that cost new investors most are consistent enough to be listed, which means they can be avoided by anyone who reads the list.

Investing money that is needed soon

The most damaging.

Money required within a few years does not belong in volatile assets, since a decline at the wrong moment cannot be recovered within the timeframe.

House deposits, wedding funds and emergency money should be in cash.

Which is the single clearest rule and the one most frequently broken during periods when markets have been rising.

Investing before clearing high-cost debt

The clearest arithmetic error.

Clearing a debt at a high rate produces a certain return equal to that rate.

Investment returns are uncertain and historically lower.

Which makes investing while carrying credit card debt a negative-expected-value activity.

The exception is capturing an employer pension match, which generally exceeds any debt rate.

Not using tax shelters first

A free improvement declined.

Tax-advantaged accounts improve net returns at no cost and with annual allowances that generally cannot be recovered once a year passes.

Investing in a taxable account while allowances remain unused is straightforwardly worse.

And employer pension matching is frequently left unclaimed by people investing elsewhere.

Paying too much

Where the damage compounds.

Expensive active funds, platform charges inappropriate to the portfolio size, frequent trading, unnecessary currency conversion and advice fees that exceed the value delivered.

Each is individually small and each compounds over decades.

Calculating total cost of ownership rather than looking at a single headline figure is the corrective.

Concentration

In several forms.

Individual shares, which carry risk that is not compensated by additional expected return.

Employer shares, which combine investment and income exposure in the same company.

A single country, particularly a small one.

A single sector or theme.

And a home, which most people do not count and which is a large leveraged undiversified holding.

Performance chasing

The most common selection error.

Buying what has recently performed well, which is when future expected returns are lower.

Selecting funds on past performance, which is a weak predictor.

Adding thematic funds after a theme has run.

And abandoning parts of a diversified portfolio that have lagged, which is the same error inverted.

Selling during declines

The most expensive.

Which converts a temporary paper loss into a permanent one and frequently produces a long period out of the market.

The correctives: an allocation you can hold, a written plan, automated contributions, and checking the portfolio less frequently.

Trading too much

Where activity correlates negatively with outcome.

Research on retail brokerage accounts consistently finds that more frequent trading produces worse net returns.

Which means the instinct to do something is generally the instinct to reduce returns.

Using leverage and complex products

Where losses concentrate.

Contracts for difference and spread betting, where regulators require disclosure of the proportion of retail accounts losing money — consistently a large majority.

Leveraged daily-reset products held for long periods.

Options without understanding them.

And anything that cannot be explained simply.

Not having a plan

The underlying error.

Investing without a stated objective, horizon, allocation and rebalancing rule means every subsequent decision is made from scratch under whatever conditions prevail.

A written plan converts decisions into comparisons against an existing framework.

Which is the single most useful thing a new investor can produce.

Falling for a scam

Which is more common than people assume.

Unsolicited approaches, guaranteed high returns, time pressure, and firms not on the regulator's register.

New investors are targeted specifically.

The two-minute check on the regulator's register prevents most of it, using the register's contact details rather than those supplied.

Waiting for a better moment

The error of omission.

Holding cash waiting for a decline, which may not arrive and which may arrive from a higher level.

Studies of investors waiting for clarity consistently find the wait costly.

The correctives are automated regular contributions and accepting that entry timing is not a solvable problem.

The short version

If only one thing is taken from this.

Clear expensive debt, hold short-term money in cash, capture the employer match, use tax shelters, buy broad low-cost global funds, contribute automatically, write down the plan, and then leave it alone.

Everything else is refinement.

General information only, not investment advice. Investments can fall in value and past performance does not indicate future returns. Consult a regulated financial adviser.