How you'll know that your banking career has been derailed before you even hit 30

If you're in your 20s and you've just started working in banking, you may feel that the world is your bivalve. In a recent pep talk to the 2013 intern class at Goldman Sachs, Lloyd Blankfein told the assembled 20-somethings that the big thing in their favour was their youth."I look around and I see people who are young," said Blankfein, adding that some of them would undoubtedly achieve more during their lives than he had in his.

But while your 20s can be a time of promise and premature achievement, it can also be a time when auspicious banking careers come to an unexpected end. These are the signs that things aren't happening as they ought to.

1. You've spent your time trying to make money instead of building your network

You may have gone into banking for the money, but you'll need to be patient. Young bankers who focus too hard on immediate rewards will suffer.

"30 is when you take off in banking," says one equity salesman, speaking on condition of anonymity. "You build goodwill between the ages of 20 and 30 and you collect that goodwill between 30 and 40.

"In your 20s, you're in survival mode," he adds. "Unless you're really, really lucky and find a good market for your product, you can't expect to make much money until you're 30. Your 20s are all about building goodwill. Don't try and cash-in too soon."

2. You've failed to find a VP or MD to be your champion

Banking career coach and ex-Goldman analyst Heather Katsonga Woodward says success in the first few years of a banking career is all about finding a vice president or management director who wants to work with you. "If your work is a high standard, you will find that an MD or VP will continually want to work with you and will invite you to meet clients. If you're mediocre, you'll find that you're not being invited to key interviews, which is an issue."

3. You've had an affair with junior colleagues and everyone knows about it

Banking is a smallish world. Misdemeanors involving colleagues will travel, especially if they concern junior colleagues - especially if, for example, if you're an associate who hits on some analysts inappropriately during a training session...

4. You've changed jobs a lot

Changing jobs frequently need not be a career killer, but it will raise eyebrows - especially if it happens more than three times in your first decade in the industry. "During interviews, people often ask me why I've switched jobs so often," says one 30-something private equity professional, speaking on condition of anonymity. "In my case it was quite straightforward - I moved to a new team following a merger, but it still raises a flag."

5. You have no decent deals on your CV

If you've worked in M&A and you haven't been picked to participate in any good deals before you reach your late 20s, you know that something's gone seriously wrong. "There's a quality-not-quantity aspect to it," says the private equity professional. "People want to see that you have some interesting and prestigious deals to talk about - you need to justify how you've spent your time in banking."

Does it matter if you've worked on some failed deals, like the Facebook IPO? Not at all. "You'd have to be good to get picked to work on something like that," the PE professional says.