The relative merits of making your investment personal

Bank stocks are like your spouse. Best you invest for a long time not a good time. They are predictable and reliable, if unexciting. They have a monopoly.

The longer you hold them the better the total return. After a long time in love and a lot of dividends, you can forgive almost any little mistakes. You are often tempted by stocks that are younger, faster and better looking, but you learn from experience that not only are they a lot more hassle but that in the long term you're going to be a lot happier with something older, wiser and more expensive. Even if it is against their better instincts, they pay out at least twice a year and sometimes surprise you with a "special". They develop an inner beauty that only long-term investors will see. Ultimately you can't imagine life without them. Sell them at your peril.

Small resources stocks are like your kids prone to hyperactivity. Some have attention deficit disorder. Most will say anything to get your money and once they've got it, you don't see them again until they need more.

The only time they behave is when they want something or are deprived of something. They are always up to mischief and often smile in a cheeky "what did you expect" fashion when they get caught. They pretend they know what they are doing even if they are making it up as they go along.

When they get bored doing what they are supposed to be doing, without shame they go and do something completely different. You only love your own, the ones that pain you the most you remember on your deathbed. A lot of us have them, wish we didn't but wouldn't have it any other way. They are a lot of fun in hindsight. You forget all the bad bits. Life would be pretty boring without them. They exhaust retirees. Some deliver huge returns.

A biotech stock is like a one-night stand. Looked really good, sounded really good, could communicate its intentions in one sentence but ultimately you invested on too little information and only realised in the cold light of day that you didn't know what you were doing.

Always memorable. Rarely something to brag about.

The conundrum is that even though they want and need to be loved for a long time, they are often gone before breakfast, taking the contents of your wallet with them. Occasionally, just occasionally, and usually when you least expect it, they can turn into a fantastic long-term investment, but this is almost always by virtue of luck not research.

Food retailers are like ladies of the night. On every street corner, open 24 hours, you go once a week and every visit costs $200.

Defensive stocks are like grand-parents undergeared and asset rich. Dividend payouts are reliable but small. If they don't squander their intrinsic value on themselves, they can sometimes pay off handsomely, but require patience.

New issues are like a secret lover. They are younger but not necessarily cheaper. You need a healthy risk appetite. They have unquestionably attractive-looking assets but you can't help thinking they've been dressed up in the short term. They have completely unproven management skills.

Availability is often more important than looks. If they're any good you won't be offered them, if you get offered them you don't want them. At the outset you are looking for a quick turn, but without a trading plan you can get trapped in a long-term investment. They become a liability the moment they go public. Do a lot of research. Sometimes the ride is worth it even if they go bust.

Stocks you have sold are like your ex. They take half your money, then the moment you're out they have a reconstruction, start looking really good and all your mates have a crack.

Marcus Padley is a stockbroker with Patersons Securities and author of sharemarket newsletter Marcus Today. For a free trial go to marcustoday.com.au. His views do not necessarily reflect those of Patersons.