In order to judge the Dow MACD extremes over time I divided the MACD values by the index values, and I listed the extreme cases. If we look at now this value is at 3.2%. There were were a few periods where it reached this level or higher:
Jul-Sep 1932 8.6%
Apr-Jul 1933 6.1%
Jun-Jul 1938 4.5%
Nov 1900 4.2%
Apr 1915 4.1%
Apr-May 1915 4.1%
Nov-Dec 1904 3.7%
Aug-Sep 1897 3.7%
Nov-Dec 1928 3.4%
Mar-Apr 1899 3.3%
Oct 1982 3.2%
Feb 1975 3.2%
Sep-Oct 1915 3.2%
Dec 1905 3.2%
Note the last of these were Oct 1982 and Feb 1975. Before this not since Jun-Jul 1938.
Now of course we got down to -12.4% on March 23, so seems natural to rebound to extremes from that oversold condition. So I looked at the top oversold cases (here we are #2) and only one exceeded this rebound, in 1932:
Nov 1929 16.6% down, 2.1% up
Mar 2020 12.4% down, 3.2% up so far
Oct 1931 11.6% down, 1.7% up
Oct 1987 10.6%, 1.5% up
Apr 1932 8.0% down, 8.6% up
I suppose this situation is absolutely unique, so we'll see how high it can get in this current ramp up.