Important: GDP is reported at a seasonally adjusted annual rate (SAAR). So a 40% Q2 decline is around 9% decline from Q1 (SA).
From Merrill Lynch:
We are tracking 2Q GDP at -40% qoq saar, down from -30% earlier. [SAAR May 22 estimate]
emphasis added
From Goldman Sachs:
We left our Q2 GDP forecast unchanged at -39% (qoq ar) but raised our estimate of the initial vintage by 0.3pp to -31.5% (released on July 30th). [May 22 estimate]
From the NY Fed Nowcasting Report
The New York Fed Staff Nowcast stands at -30.5% for 2020:Q2. [May 22 estimate]
And from the Altanta Fed: GDPNow
The GDPNow model estimate for real GDP growth (seasonally adjusted annual rate) in the second quarter of 2020 is -41.9 percent May 19, up from -42.8 percent on May 15. [May 19 estimate]