Going back to the start of the 2018 season gives us a sizable database to work with, and thus the findings should be of value.
Overall records of streaking teams
Lost 4: 399-467, +14.4 units, ROI: 1.7%
Lost 5: 212-250, +16.4 units, ROI: 3.5%
Lost 6: 122-126, +34.45 units, ROI: 13.9%
Lost 7: 66-59, +31.3 units, ROI: 25.0%
Lost 8: 35-24, +23.6 units, ROI: 40.0%
Lost 9: 16-8, +17.2 units, ROI: 71.7%
Lost 10: 6-2, +8 units, ROI: 100.0%
Won 4: 479-419, -48.65 units, ROI: -5.4%
Won 5: 250-226, -39.85 units, ROI: -8.4%
Won 6: 120-129, -48.95 units, ROI: -19.7%
Won 7: 64-56, -7.15 units, ROI: -6.0%
Won 8: 30-34, -13.25 units, ROI: -20.7%
Won 9: 14-16, -4.7 units, ROI: -15.7%
Won 10: 6-8, -5.05 units, ROI: -36.1%