Boglehead Contest

Boglehead Contest logo

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.

The rules of the contest are simple:

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

Records of annual contest entries cover the period from 2003 to 2018, so an analysis of participant performance is possible. As of 2018, 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

Average results

The table below provides the average guess by each group (bogleheads vs. experts). Over the 2003 – 2018 period, the bogleheads have, on average, come closer to guessing the S&P 500 closing value nine times; the experts seven times. The average point variance from the closing index value has also been rather close: the boglehead difference has averaged 159.95 points; the experts 165.81.

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
Average				186.46	167.72

The average guesses allow us to also calculate an implied return guess. The following table (the “winning” average is high-lighted in blue) 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 return	Experts return
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%
Average		6.13%	8.83%