Boglehead Contest

The Boglehead Contest is an annual event that takes place on the Bogleheads forum where members take guesses to forecast the closing price of the S&P 500 Price Index at year end. Keep in mind that the Price Index is simply a measure of market price and does not take into account stock dividends or the reinvestment of dividends. Thus, the Price Index does not represent the total return for an investment in an S&P 500 index fund.

The contest also includes forecast predictions from “expert” Wall Street firms, and the comparison between the amateur and expert camps is considered a fun distraction looking at the potential follies of making predictions (see Morgan Housel’s similar take on forecasting stock prices in The Blind Forecaster).

The rules of the contest are simple:

1. Guess the closing price of the S&P 500 Price Index on December 31 of the year in question.
2. Only one guess (no percentages) is allowed.
3. Registration closes on midnight January 10 of the given year.
4. In event of ties, the first guess wins.

Records of annual contest entries cover the period from 2003 to 2021, so an analysis of participant performance is possible. As of 2021, no individual winner of the contest has been able to repeat.

Boglehead Contest annual winners

Year	Winner	Guess	S&P 500	Difference
2003	dalevvitt	1112.00	1111.91	0.09
2004	scanchain	1212.00	1211.23	0.77
2005	keithlommel	1248.16	1248.23	0.07
2006	Ken969	1419.24	1418.30	0.94
2007	schellase	1467.00	1468.36	1.36
2008	Betelgeuse	876.00	903.25	27.25
2009	mmg	1117.00	1115.10	1.90
2010	gordo	1258.00	1257.64	0.36
2011	Triple digit golfer	1257.61	1257.30	0.31
2012	TAINTED MEAT	1426.31	1426.20	0.11
2013	peppers	1854.20	1848.36	5.84
2014	FinacialDave	2057.36	2059.90	2.54
2015	VictoriaF	2048.00	2043.94	4.06
2016	Roverdog	2238.89	2238.83	0.06
2017	Bruce	2676.10	2673.61	2.49
2018	pjtallman	2512.00	2506.85	5.15
2019	buylowbuyhigh	3324.00	3230.78	6.78
2020	Mlretired	3755.00	3756.07	1.07
2021	auntie	4770.30	4766.18	4.12

Average results

The table below provides the average guess by each group (bogleheads vs. experts). Over the 2003 – 2021 period, the bogleheads have, on average, come closer to guessing the S&P 500 closing value ten times; the experts nine times. The average point variance from the closing index value: the boglehead difference has averaged 230.10 points; the experts 179.36.

Boglehead Contest average guess

Year	S&P 500 return	Bogleheads avg. guess	Experts avg. guess	Bogleheads difference	Experts difference
2002	879.82
2003	1111.91	942.81	1019.09	169.10	92.82
2004	1211.23	1200.75	1114.67	10.48	96.56
2005	1248.23	1265.25	1273.50	17.02	25.27
2006	1418.30	1305.97	1345.83	112.33	72.47
2007	1468.36	1488.84	1539.47	20.48	71.11
2008	903.25	1512.07	1647.39	608.82	744.14
2009	1115.10	1015.30	1045.42	99.80	69.68
2010	1257.64	1212.37	1223.00	45.27	34.64
2011	1257.30	1357.01	1336.67	99.71	79.37
2012	1426.20	1383.97	1367.71	42.23	58.49
2013	1848.36	1532.06	1525.91	316.30	322.45
2014	2059.90	1958.40	1949.14	101.50	110.76
2015	2043.94	2126.93	2219.53	82.99	175.59
2016	2238.83	2108.05	2192.50	130.78	46.33
2017	2673.61	2303.26	2359.18	370.35	314.43
2018	2506.85	2832.49	2840.92	325.64	334.07
2019	3230.78	2613.71	3027.69	617.07	203.09
2020	3756.07	3369.14	3300.00	386.93	456.07
2021	4766.18	3955.23	4055.71	810.95	100.48
Average				230.10	179.36

The average guesses allow us to also calculate an implied return guess. The following table (the “winning” average is high-lighted in bold provides this return forecast data. Note that over this period both bogleheads and experts have, on average, always forecast a bullish positive return.

Boglehead Contest implied S&P 500 Price Index returns

Year	S&P 500 return	Bogleheads	Experts
2002
2003	26.38%	7.16%	15.83%
2004	8.93%	7.99%	0.25%
2005	3.05%	4.46%	5.14%
2006	13.62%	4.63%	7.82%
2007	3.53%	4.97%	8.54%
2008	-38.49%	2.98%	12.19%
2009	23.45%	12.41%	15.74%
2010	12.78%	8.72%	9.68%
2011	-0.03%	7.90%	6.28%
2012	13.43%	10.07%	8.78%
2013	29.60%	7.42%	6.99%
2014	11.44%	5.95%	5.45%
2015	-0.77%	3.25%	7.75%
2016	9.54%	3.14%	7.27%
2017	19.42%	2.88%	5.38%
2018	-6.24%	5.94%	6.26%
2019	28.88%	4.26%	20.78%
2020	16.26%	4.28%	2.14%
2021	27.00%	5.30%	7.98%
Average	10.68%	5.99%	8.43%

This bullish tendency is captured in these charts, which measure individual forecasts (click image to enlarge).

Additional information

• Boglehead Contest (official site)
• Bogleheads® contests – wiki
• 2022 Boglehead Contest Charts – forum
• 2021 Boglehead Contest Charts – forum
• 2019 Boglehead Contest Charts – forum
• 2018 Boglehead Contest Charts – forum
• 2017 Boglehead Contest Charts – forum
• 2016 Boglehead Contest Charts – forum
• Boglehead Contest (google sheet)

Reference links