How is portfolio return calculated?

So I get that return is just (final - initial) / initial.

But what if investments are made yearly?

Say for example, $100 is invested on Jan 1st each year in the S&P500
Assuming the S&P500 gives 10% return each year, on Dec 31st of y1, the portfolio value is $110, but tomorrow, when the y2 investment of $100 comes in, it becomes $210. Does this mean that the portfolio return is now (210-200)/200 = 5%?

My guess is that something's got to do with IRR? But I can't reconcile the idea of IRR (which I only know how to apply to negative initial cash flows and positive after some given time) to portfolio return (where its positive due to $100 investment and positive due to $10 return)

If anyone can help out here, I'd greatly appreciate it!

1 Comments
 

Labore eaque dignissimos explicabo impedit non voluptatem consectetur. Nesciunt ab tenetur id. Dolorem adipisci neque qui corporis.

Fuga quis consequatur sapiente. Soluta animi qui molestiae.

Career Advancement Opportunities

August 2026 Investment Banking

  • Evercore 01 99.5%
  • Moelis & Company 01 98.9%
  • JPMorgan 01 98.4%
  • Morgan Stanley 08 97.8%
  • Goldman Sachs 02 97.3%

Overall Employee Satisfaction

August 2026 Investment Banking

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

Professional Growth Opportunities

August 2026 Investment Banking

  • Evercore 01 99.5%
  • Moelis & Company 01 98.9%
  • Morgan Stanley 06 98.4%
  • Goldman Sachs 01 97.8%
  • JPMorgan 01 97.3%

Total Avg Compensation

August 2026 Investment Banking

  • Vice President (16) $429
  • Associates (48) $259
  • 3rd+ Year Analyst (8) $210
  • 2nd Year Analyst (25) $178
  • Intern/Summer Associate (14) $159
  • 1st Year Analyst (83) $151
  • Intern/Summer Analyst (75) $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
Secyh62's picture
Secyh62
99.0
3
kanon's picture
kanon
99.0
4
BankonBanking's picture
BankonBanking
99.0
5
DrApeman's picture
DrApeman
98.9
6
CompBanker's picture
CompBanker
98.9
7
dosk17's picture
dosk17
98.9
8
GameTheory's picture
GameTheory
98.9
9
Betsy Massar's picture
Betsy Massar
98.9
10
Mimbs's picture
Mimbs
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...”