Would I Use Up My Savings Withdrawing 4% Annually During Market Downturns?

I am not sure, so let's assume I withdraw 4% of my savings at the high right before the 2008 Housing Bubble or the 2000 Recession. And assume my savings are IVV, an S&P 500 tracking ETF.

Simulation Setup

2008 Case

• High: Oct 09, 2007; IVV was traded at $156.79
• My fund has $1k, which is made up of 6.37796 shares of IVV
• Start withdrawing $40 from the fund on Oct 09, 2007
• * means dividend reinvestment
• All prices are IVV's daily closing price.

2008 Case Calculation

My fund has grown back to $1,011.77 on Jun 24, 2015, bigger than what I started. I don't think I will use up my fund anytime soon.

Date	IVV Shares	IVV Price	Total Value
Oct 09, 2007	6.12284	$156.79	$960.00
Dec 27, 2007	6.15582*	$148.13	$911.86
Mar 25, 2008	6.18716*	$135.32	$837.25
Jun 24, 2008	6.21969*	$131.46	$817.64
Sep 25, 2008	6.25455*	$121.15	$757.74
Oct 09, 2008	5.81925	$91.89	$534.73
Dec 24, 2008	5.86361*	$86.85	$509.25
Mar 25, 2009	5.90365*	$81.57	$481.56
Jun 23, 2009	5.93526*	$89.64	$532.04
Sep 23, 2009	5.96450*	$106.56	$635.58
Oct 09, 2008	5.59258	$107.55	$601.48
Dec 24, 2009	5.62219*	$112.93	$634.91
Mar 25, 2010	5.64607*	$117.01	$660.65
Jun 23, 2010	5.67163*	$109.58	$621.50
Sep 24, 2010	5.70247*	$115.14	$656.58
Oct 08, 2010	5.36036	$116.92	$626.73
Dec 23, 2010	5.38655*	$126.09	$679.19
Mar 25, 2011	5.41104*	$131.73	$712.80
Jun 23, 2011	5.43647*	$128.75	$699.95
Sep 26, 2011	5.46585*	$116.59	$637.26
Oct 07, 2011	5.12123	$116.07	$594.42
Dec 22, 2011	5.15258*	$125.80	$648.19
Mar 26, 2012	5.17550*	$142.06	$735.23
Jun 19, 2012	5.19977*	$136.27	$708.57
Sep 25, 2012	5.22843*	$144.76	$756.87
Oct 09, 2012	4.95226	$144.84	$717.29
Dec 19, 2012	4.98424*	$144.03	$717.88
Mar 25, 2013	5.00801*	$155.82	$780.35
Jun 26, 2013	5.03315*	$160.97	$810.19
Sep 24, 2013	5.05779*	$170.54	$862.56
Oct 09, 2013	4.81754	$166.49	$802.07
Dec 23, 2013	4.84270*	$183.59	$889.07
Mar 25, 2014	4.86416*	$187.49	$911.98
Jun 24, 2014	4.88687*	$196.00	$957.83
Sep 24, 2014	4.90959*	$200.89	$986.28
Oct 09, 2014	4.70330	$193.90	$911.97
Dec 24, 2014	4.72809*	$209.29	$989.54
Mar 25, 2015	4.75096*	$207.19	$984.35
Jun 24, 2015	4.77746*	$211.78	$1,011.77

2000 Case

• High: Jul 14, 2000; IVV was traded at $150.98
• My fund has $1k, which is made up of 6.62339 shares of IVV
• Start withdrawing $40 from the fund on Jul 14, 2000
• * means dividend reinvestment
• All prices are IVV's daily closing price.

2000 Case Calculation

My fund has grown back to $1,029.41 on Jun 10, 2021, bigger than what I started. I don't think I will use up my fund anytime soon.

Date	IVV Shares	IVV Price	Total Value
Jul 14, 2000	6.35845	$150.98	$960.00
Sep 20, 2000	6.37060*	$144.98	$923.61
Dec 13, 2000	6.39120*	$135.78	$867.80
Mar 12, 2001	6.40439*	$117.78	$754.31
Jun 11, 2001	6.42231*	$125.77	$807.73
Jun 14, 2001	6.09339	$121.61	$741.02
Oct 02, 2001	6.11609*	$105.51	$645.31
Dec 17, 2001	6.13436*	$113.85	$698.40
Mar 11, 2002	6.14974*	$116.89	$718.84
Jun 17, 2002	6.17183*	$103.84	$640.88
Jul 15, 2002	5.73794	$92.19	$528.98
Sep 16, 2002	5.76321*	$89.47	$515.63
Dec 16, 2002	5.78993*	$91.25	$528.33
Mar 10, 2003	5.81388*	$81.00	$470.95
Jun 16, 2003	5.83493*	$101.36	$591.43
Jul 15, 2003	5.43696	$100.51	$546.47
Sep 15, 2003	5.45946*	$101.72	$555.34
Dec 15, 2003	5.48565*	$107.14	$587.73
Dec 16, 2003	5.55054*	$107.74	$598.02
Mar 29, 2004	5.56971*	$112.64	$627.37
Jun 28, 2004	5.58959*	$113.48	$634.31
Jul 15, 2004	5.22842	$110.75	$579.05
Sep 27, 2004	5.25031*	$110.83	$581.89
Dec 27, 2004	5.28707*	$120.69	$638.10
Mar 28, 2005	5.32049*	$117.23	$623.72
Jun 21, 2005	5.33744*	$121.48	$648.39
Jul 15, 2005	5.01187	$122.86	$615.76
Sep 26, 2005	5.03265*	$121.56	$611.77
Dec 23, 2005	5.05303*	$126.95	$641.48
Mar 27, 2006	5.07313*	$130.25	$660.78
Jun 23, 2006	5.09462*	$124.67	$635.15
Jul 14, 2006	4.77152	$123.80	$590.71
Sep 27, 2006	4.79357*	$133.96	$642.15
Dec 21, 2006	4.81748*	$141.96	$683.89
Mar 26, 2007	4.83901*	$143.42	$694.01
Jun 29, 2007	4.86045*	$150.51	$732.55
Jul 16, 2007	4.60247	$155.05	$713.61
Sep 26, 2007	4.62320*	$152.55	$705.27
Dec 27, 2007	4.64811*	$148.13	$688.52
Mar 25, 2008	4.67178*	$135.32	$628.13
Jun 24, 2008	4.69424*	$131.46	$617.10
Jul 14, 2008	4.36930	$123.10	$537.86
Sep 25, 2008	4.39379*	$121.15	$532.31
Dec 24, 2008	4.42728*	$86.85	$384.51
Mar 25, 2009	4.45751*	$81.57	$363.60
Jun 23, 2009	4.48212*	$89.64	$401.78
Jul 14, 2009	4.04237	$90.96	$367.69
Sep 23, 2009	4.06229*	$106.56	$432.88
Dec 24, 2009	4.08380*	$112.93	$461.18
Mar 25, 2010	4.10115*	$117.01	$479.88
Jun 23, 2010	4.11971*	$109.58	$451..44
Jul 14, 2010	3.75621	$110.04	$413.33
Sep 24, 2010	3.77663*	$115.14	$434.84
Dec 23, 2010	3.79508*	$126.09	$478.52
Mar 25, 2011	3.81234*	$131.73	$502.20
Jun 23, 2011	3.83025*	$128.75	$493.14
Jul 14, 2011	3.52586	$131.41	$463.33
Sep 26, 2011	3.54491*	$116.59	$413.30
Dec 22, 2011	3.56661*	$125.80	$448.68
Mar 26, 2012	3.58248*	$142.06	$508.93
Jun 19, 2012	3.59928*	$136.27	$490.47
Jul 13, 2012	3.30581	$136.30	$450.58
Sep 25, 2012	3.32403*	$144.76	$481.19
Dec 19, 2012	3.34549*	$144.03	$481.85
Mar 25, 2013	3.36144*	$155.82	$523.78
Jun 26, 2013	3.37831*	$160.97	$543.81
Jul 15, 2013	3.14183	$169.15	$531.44
Sep 24, 2013	3.15721*	$170.54	$538.43
Dec 23, 2013	3.17370*	$183.59	$582.66
Mar 25, 2014	3.18777*	$187.49	$597.67
Jun 24, 2014	3.20265*	$196.00	$627.72
Jul 14, 2014	3.00149	$198.85	$596.85
Sep 24, 2014	3.01544*	$200.89	$605.77
Dec 24, 2014	3.03133*	$209.29	$634.43
Mar 25, 2015	3.04599*	$207.19	$631.10
Jun 24, 2015	3.06298*	$211.78	$648.68
Jul 14, 2015	2.87427	$211.97	$609.26
Sep 25, 2015	2.89031*	$193.85	$560.29
Dec 24, 2015	2.90690*	$206.83	$601.23
Dec 29, 2015	2.90955*	$208.51	$606.67
May 23, 2016	2.91121*	$206.26	$600.47
Jun 21, 2016	2.92507*	$209.62	$613.15
Jul 14, 2016	2.74104	$217.35	$595.77
Sep 26, 2016	2.75507*	$215.45	$593.58
Dec 21, 2016	2.77088*	$227.18	$629.49
Mar 24, 2017	2.78303*	$235.39	$655.10
Jun 27, 2017	2.79582*	$243.04	$679.50
Jul 14, 2017	2.63394	$247.10	$650.85
Sep 26, 2017	2.64743*	$250.75	$663.84
Dec 19, 2017	2.65995*	$269.13	$715.87
Mar 22, 2018	2.67226*	$265.47	$709.40
Jun 26, 2018	2.68478*	$273.47	$734.21
Jul 13, 2018	2.54265	$281.43	$715.58
Sep 26, 2018	2.55377*	$292.02	$745.75
Dec 17, 2018	2.56817*	$255.65	$656.55
Mar 20, 2019	2.57841*	$283.39	$730.70
Jun 17, 2019	2.59423*	$289.74	$751.65
Jul 15, 2019	2.46198	$302.46	$744.65
Sep 24, 2019	2.47425*	$297.51	$736.11
Dec 16, 2019	2.49005*	$319.32	$795.12
Mar 25, 2020	2.50545*	$247.47	$620.03
Jun 15, 2020	2.51574*	$306.89	$772.06
Jul 14, 2020	2.39081	$320.17	$765.47
Sep 23, 2020	2.40193*	$323.75	$777.62
Dec 14, 2020	2.41254*	$364.35	$879.01
Mar 25, 2021	2.42063*	$391.12	$946.76
Jun 10, 2021	2.42762	$424.04	$1,029.41

Conclusion

Withdrawing 4% from a fund made of pure IVV during highs of 2000 and 2008 would not have made me penniless.