Is investing in what you know a dangerous thing?

I have learnt that it is best to invest in what you know (the business). But in an article I read that even Warren Buffett stands by it that it's dangerous to invest in what you know. Is that right?

3 Comments
 
Most Helpful

It would be smart to invest in what you know, but I guess limiting yourself to investing in what you know can be dangerous in two ways according to me (and maybe that’s what buffet’s going for?): 1. You become narrow minded and miss out on potential opportunities that you can make a lot of money on i.e. instead of just investing in what you know, you can try to understand other businesses and make investments in them. 2. If you only invest in what you know, after a while, you might think that because of your understanding of the industry/sector, you might be able to come up with some short cut way to decide whether a business is a good investment or not, whereas in reality it takes time to go through the financials and understand each unique company

I haven’t heard buffet say this, but if he did, I guess this is what I would infer

 

Under the CAPM and the EMH, it is assumed that the average market participant's portfolio is well diversified. This means the average portfolio's risk is equal to the market risk. Therefore, investors are not concerned with idiosyncratic risk and the market doesn't compensate them for it.

If your strategy is to only invest in what you know, your portfolio is not going to be well diversified. You'd have to believe that markets are inefficient and that you can identify alpha opportunities that would generate greater returns than the market. The belief that markets are inefficient is needed for there to be alpha opportunities.

It's a dumb strategy if you think markets are efficient or if you're not adept enough to identify alpha opportunities. **It's dangerous to the extent that markets are efficient and that you are unable to identify alpha. **

 

Aut similique amet harum omnis qui. Laudantium explicabo aut quisquam ut cupiditate. Autem repellendus iure ut quisquam. Odit in eum ipsum est. Fugiat dolorem saepe quis. Doloribus et pariatur eum ut. Est eaque nemo et repudiandae quaerat.

Sunt nostrum sint voluptas fuga porro at voluptatem repellendus. Aspernatur quia numquam dolor non nam voluptatem officiis.

Career Advancement Opportunities

September 2026 Investment Banking

  • Evercore 01 99.5%
  • Moelis & Company 01 98.9%
  • JPMorgan 01 98.4%
  • Goldman Sachs 01 97.8%
  • Morgan Stanley 07 97.3%

Overall Employee Satisfaction

September 2026 Investment Banking

  • Moelis & Company No 99.5%
  • Morgan Stanley 02 98.9%
  • Evercore 01 98.4%
  • Banco Santander 02 97.8%
  • BMO Capital Markets 12 97.3%

Professional Growth Opportunities

September 2026 Investment Banking

  • Evercore 01 99.5%
  • Moelis & Company 01 98.9%
  • Morgan Stanley 07 98.4%
  • Goldman Sachs 01 97.8%
  • JPMorgan No 97.3%

Total Avg Compensation

September 2026 Investment Banking

  • Vice President (16) $429
  • Associates (51) $260
  • 3rd+ Year Analyst (8) $210
  • 2nd Year Analyst (26) $182
  • Intern/Summer Associate (14) $159
  • 1st Year Analyst (84) $151
  • Intern/Summer Analyst (76) $101
notes
16 IB Interviews Notes

“... there’s no excuse to not take advantage of the resources out there available to you. Best value for your $ are the...”

Leaderboard

1
redever's picture
redever
99.2
2
BankonBanking's picture
BankonBanking
99.0
3
kanon's picture
kanon
99.0
4
Secyh62's picture
Secyh62
99.0
5
Betsy Massar's picture
Betsy Massar
98.9
6
CompBanker's picture
CompBanker
98.9
7
GameTheory's picture
GameTheory
98.9
8
dosk17's picture
dosk17
98.9
9
DrApeman's picture
DrApeman
98.9
10
numi's picture
numi
98.8
success
From 10 rejections to 1 dream investment banking internship

“... I believe it was the single biggest reason why I ended up with an offer...”