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I don't understand the following charts, and wondered if someone could explain to me why they seem inconsistent with one another.

Context: While doing research recently into a mutual fund SGENX, Google Finance produced the following performance chart:

SGENX vs S&P 500 chart

Which shows it beating the S&P 500 Index. Later on I did another comparison with the Vanguard ETF VOO and got this chart:

SGENX-vs-VOO

This confused me because the VOO should mirror the S&P 500 index. Which I verified by comparing it directly to the index:

VOO-vs-S&P-500-Index

As a final check I compared them (along with another Vanguard "Extend Market" ETF) on eTrade and got this combined chart:

eTrade-SGENX-Comparison

Which seems to show that VOO outperformed SGENX (however it also looks like VOO outperformed the S&P Index slightly — which also seems a little odd).

What am I missing here?

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    What you're missing is that the timescale is quite different on your different charts. Also be careful of price vs total return... but the timescale is definitely your issue. "Max" (which is shorthand for "since inception") means different things depending on what equity you are plotting. – Ben Voigt Oct 3 at 18:11
  • @BenVoigt: The first three are all "Max" time scales, so it is an apples-to-apples comparison. The final eTrade chart is only 10 years because their tools didn't offer that option (and that chart final chart was just a sanity-check). So, either I don't understand or what you're saying doesn't appear to be correct. – martineau Oct 3 at 18:19
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    @martineau Look at the date axis on the second chart. It only goes back to 2010/2011 (where VOO starts), while the top chart goes back to somewhere around 2000. – D Stanley Oct 3 at 18:42
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Your time scales are not the same. In both charts you have "Max" selected for the time scale. However, chart 1 goes back to ~2000 and chart 2 goes back to ~2011 (these dates match the inception dates for SGENX and VOO). With different time periods it makes sense why they don't match.

When I plot the exact same thing except I select 5 years as the time period, the charts are essentially the same.

enter image description here

enter image description here

  • Thanks. Obviously, when doing a "Max" comparison, the time scale will be limited by the actual inception date of the youngest item when comparing two or more of them. However, your answer presents compelling evidence you're correct — so I'll probably accept it — although it still seems to me that whether I select "Max" or a specific period of time, the overall comparison would be much more similar than the first two charts in my question where the results are completely reversed. – martineau Oct 3 at 18:59
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    @martineau If you look at your first chart from about 2011 onward, the S&P500 has a greater increase than SGENX (it "closes the gap" so to speak), this matches what you see in the second chart. It is sort of confusing, but the data checks out. – Nosjack Oct 3 at 20:20
  • Nosjack: I think I get it now, thanks for the follow-up. So I take it one can only conclude that, with respect to the last 5 years anyway, the S&P index has been doing much better than the fund but — despite that — investing SGENX back when it was created 20 or so years ago would have been the better overall investment. Right? – martineau Oct 3 at 20:41
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    @martineau Looking at the start and end points, that's correct. Also, 2011 is about the time the trend reversed (S&P500 began to beat SGENX), just by eye-balling chart 1. This also helps explain why the difference between the two graphs is so severe (that's about when the second chart begins). – Nosjack Oct 3 at 20:51

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