Spero Therapeutics Inc (SPRO) Earnings

2.28 ↑0.00 (0.00%)

As of December 31, 1969, 7:00pm EST.

Last earnings report date: 0000-00-00Next earnings report date: N/A

Should You Buy SPRO Before Earnings?

Based on the last three years of earnings reports, buying SPRO stock within four weeks before its earnings date yielded an average return of 0.30%.

The best time to buy before earnings was 14 days before, which yielded an average return of 1.04% by the earnings date. The worst time was 28 days before, which yielded an average return of -0.41%.

Report dates analyzed: Mar 29 2023 - Nov 17 2025*

Disclaimer: Past performances is not a guarantee of future results.

Should You Buy SPRO After Earnings?

Based on the last three years of earnings reports, on average, SPRO has gone up 0.43% shortly after its earnings date. The price peaks 28 days after earnings and is on average 1.56% higher than its closing price on day of earnings.

Since SPRO has typically gone up after earnings, you might want to consider buying the stock before.

Report dates analyzed: Nov 8 2022 - Aug 7 2025*

Disclaimer: Past performances is not a guarantee of future results.

Average Gains

The average return if you bought Spero Therapeutics before its earnings report and sold at close on its earnings day.

Period	28 Day Before	21 Days Before	14 Days Before	7 Days Before	1 Day Before	Day Of
Past 4 Earnings	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%
Past 8 Earnings	-0.33%	0.71%	0.97%	-0.54%	0.00%	-0.11%
Past 12 Earnings	-0.49%	0.04%	1.08%	-0.24%	0.64%	-0.16%

SPRO Earnings History

Report Date	28 Day Before	21 Days Before	14 Days Before	7 Days Before	1 Day Before	Day Of	1 Day After	7 Days After	14 Days After	21 Days After	28 Days After
2025-11-17	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A
2025-08-07	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A
2025-05-13	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A
2025-03-11	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A
2024-11-11	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A
2024-08-08	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A
2024-05-09	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A
2024-03-28	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A
2023-11-13	1.14 -2.63%	1.05 5.71%	1.03 7.77%	1.16 -4.31%	1.11 0.00%	1.11 -0.89%	1.09 -1.80%	1.23 10.81%	1.17 5.41%	1.23 10.81%	1.28 15.32%
2023-08-08	1.55 -4.52%	1.50 -1.33%	1.41 4.97%	1.52 -2.63%	1.50 -1.33%	1.48 0.00%	1.45 -2.03%	1.35 -9.12%	1.31 -11.49%	1.37 -7.43%	1.43 -3.38%
2023-05-15	1.76 6.25%	1.71 9.36%	1.85 1.08%	1.90 -1.58%	1.85 1.08%	1.87 0.00%	1.79 -4.28%	1.91 2.14%	1.77 -5.35%	1.77 -5.35%	1.75 -6.42%

Methodology

We analyzed the past three years of SPRO's earnings reports to calculate the average change in price of the stock before and after earnings.

Before Earnings

For calculating the average gains if you bought prior to earnings, we looked at the closing price of 5 different dates and compared them to the closing price of SPRO on the day of the earnings report to calculate the return. The dates analyzed are:

28 days prior (4 weeks)
21 days prior (3 weeks)
14 days prior (2 weeks)
7 days prior (1 week)
1 day prior

This simulates an individual purchasing SPRO stock on one of those days and selling on the day of the earnings report.

After Earnings

For calculating the average gains if you bought SPRO stock on the day of earnings, we looked at the closing price of SPRO on the day of the earnings and then compared it to 5 dates after. The dates analyzed are:

1 day after
7 days after (1 week)
14 days after (2 weeks)
21 days after (3 weeks)
28 day after (4 weeks)

This simulates an individual purchasing SPRO stock on the day of the earnings report and then selling on one of the dates following.

Day of

To calculate the gains on the day of earnings, we compared the opening price of SPRO to the closing price on the day of earnings - regardless if the earnings call was pre- or post-market.