Last edited Wed Jul 12, 2023, 11:16 PM - Edit history (2)
So the purchasing power of the total U.S. stock market fund is up 1.10% since inflation began in about January 2021... that is, since inflation consistently above the 2% target began.
The market: VTSAX Vanguard Total Stock Market Index Fund (total U.S. stock market)
https://finance.yahoo.com/quote/VTSAX/history
Using the Adjusted Close figures which are adjusted for reinvested dividends. Thus these are total return figures:
1/1/21: 91.66
7/12/23: 107.42
+17.19%
Inflation: CPI:
https://data.bls.gov/timeseries/CUSR0000SA0
1'21: 262.650 (1'21 means January 2021)
6'23: 303.841
7'23: 304.449 (I just made it 0.2% higher than 6'23)
+15.91%
Real (inflation-adjusted) market up 107.42/91.66 * 262.650/304.449 = 1.01104 => 1.10%.
As for when sustained inflation above the Fed's 2.0% target began: It went above the pre-pandemic approximately 2.0% trendline in around January-February 2021
https://fred.stlouisfed.org/series/CPIAUCSL
IMGUR beginning May 2017 
One has to get their straight edge out -- I couldn't figure out how to draw a straight line on the graph at IMGUR or the Windows Snip Tool.
I've also looked at every CPI graph from month-by-month to rolling 3 month averages, 6 month averages, 12 month averages, even rolling 36 month averages, so I'm comfortable that January 2021 is close.
Another interesting thing about the above graph is that the inflection point where inflation began a marked slowdown is clear on the graph: around June or July 2022. That X-axis label that is obscured by the "i" in Picsart is July 2022, and that's about where the "kink" is. No surprise: the month over month figures in May 2022 is 0.9% and June is 1.2%, followed by 0.0% and 0.2% in July and August 2022 respectively, making for a rather sharp change in slope.
As for the current CPI and core CPI trends (in the past 13 months or so):
https://www.democraticunderground.com/10143099462#post12
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