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Alector, Inc. (ALEC) Annual Reports

Q: Where can I read Alector, Inc. (ALEC) annual reports?

Every year on this page links straight to the full text on SEC EDGAR. US annual reports are web pages (HTML) rather than PDFs, so you can read and search them in the browser. 3 filings are currently indexed.

Q: What is the difference between a 10-K and a 20-F?

A 10-K is the annual report of a US domestic issuer; a 20-F is filed by foreign private issuers (Taiwanese companies with US ADRs, such as TSMC, file 20-F). A 40-F applies to Canadian issuers under the MJDS.

Alector, Inc. is listed on Nasdaq, classified by the SEC under Biological Products, (No Diagnostic Substances) (SIC 2836). This page indexes 3 annual reports, each linking to the full text on the SEC's EDGAR system.

Company profile

Exchange： Nasdaq
Fiscal year end： 12/31
SEC CIK： 1653087 →

Website：Official site ↗

Financial Highlights

FY2026 Q2 (quarterly, ended 2026-06-30)
	Current	Prior year	YoY
Revenue	$3.3M	$7.9M	-57.8%
Operating income	$-24.4M	$-34.1M	+28.5%
Net income	$-23.0M	$-30.5M	+24.7%
EPS (diluted)	$-0.21	$-0.30	+30.0%

Source: SEC EDGAR (XBRL company facts)

Financial history

Revenue & profit

Quarterly · In mn (USD)

Revenue 3.32 mn Net income -23.0 mn

Show table：Income statement

Item	2017Q4	2018Q1	2018Q2	2018Q3	2018Q4	2019Q1	2019Q2	2019Q3	2019Q4	2020Q1	2020Q2	2020Q3	2020Q4	2021Q1	2021Q2	2021Q3	2021Q4	2022Q1	2022Q2	2022Q3	2022Q4	2023Q1	2023Q2	2023Q3	2023Q4	2024Q1	2024Q2	2024Q3	2024Q4	2025Q1	2025Q2	2025Q3	2025Q4	2026Q1	2026Q2
Revenue	2.87	4.75	7.11	6.50	9.15	5.61	6.92	2.70	6.00	7.17	3.17	5.90	4.85	4.11	6.57	182	14.0	24.5	79.8	14.8	14.4	16.6	56.2	9.11	15.2	15.9	15.1	15.3	54.2	3.67	7.87	3.26	6.24	1.05	3.32
Operating income	-32.7	-9.22	-12.2	-16.8	-19.0	-20.8	-27.1	-34.1	-32.3	-42.1	-46.6	-53.8	-52.8	-52.6	-55.3	126	-55.7	-44.1	9.48	-47.8	-55.4	-50.1	-3.59	-50.6	-47.5	-43.7	-45.6	-48.4	-7.25	-44.7	-34.1	-37.6	-39.6	-24.9	-24.4
Net income	-32.5	-8.44	-11.1	-15.3	-17.4	-18.6	-24.6	-31.7	-30.5	-40.0	-45.3	-52.7	-52.2	-52.2	-55.1	127	-55.6	-44.6	9.88	-46.1	-52.4	-45.9	1.38	-44.5	-41.4	-36.1	-38.7	-42.2	-2.07	-40.5	-30.5	-34.7	-37.3	-22.9	-23.0

Balance sheet

Quarterly · In mn (USD)

Total assets 203 mn Total liabilities 213 mn

Equity = assets − liabilities. Balance-sheet figures are period-end balances, not cumulative.

Show table：Balance sheet

Item	2017Q4	2018Q1	2018Q2	2018Q3	2018Q4	2019Q1	2019Q2	2019Q3	2019Q4	2020Q1	2020Q2	2020Q3	2020Q4	2021Q1	2021Q2	2021Q3	2021Q4	2022Q1	2022Q2	2022Q3	2022Q4	2023Q1	2023Q2	2023Q3	2023Q4	2024Q1	2024Q2	2024Q3	2024Q4	2025Q1	2025Q2	2025Q3	2025Q4	2026Q1	2026Q2
Current assets	—	—	—	—	293	442	415	385	357	556	510	470	422	375	329	788	750	891	827	775	726	686	648	613	566	581	520	469	425	367	319	300	266	215	180
Total assets	—	—	—	—	308	496	477	450	422	619	572	532	488	440	397	854	815	954	890	837	788	748	709	672	622	635	571	516	468	408	356	335	293	240	203
Current liabilities	—	—	—	—	48.0	55.8	67.1	58.7	62.0	71.8	65.9	71.1	68.1	64.1	74.4	133	140	143	149	161	93.8	99.3	132	155	178	165	148	143	125	110	84.3	80.0	69.5	41.0	34.2
Total liabilities	—	—	—	—	195	230	232	231	227	227	217	221	221	213	213	518	514	687	601	584	573	565	512	510	488	457	420	397	342	314	285	278	263	230	213
Equity	-52.0	-59.5	-69.4	-82.8	-97.4	266	246	219	195	392	355	310	268	228	185	336	301	268	289	253	214	183	196	163	134	179	151	119	127	94.6	71.2	57.7	30.6	10.4	-9.97

Cash flow

Quarterly · In mn (USD)

Operating -34.2 mn Investing 17.1 mn Financing 0.05 mn

Positive = cash in, negative = cash out.

Show table：Cash flow statement

Item	2017Q4	2018Q1	2018Q2	2018Q3	2018Q4	2019Q1	2019Q2	2019Q3	2019Q4	2020Q1	2020Q2	2020Q3	2020Q4	2021Q1	2021Q2	2021Q3	2021Q4	2022Q1	2022Q2	2022Q3	2022Q4	2023Q1	2023Q2	2023Q3	2023Q4	2024Q1	2024Q2	2024Q3	2024Q4	2025Q1	2025Q2	2025Q3	2025Q4	2026Q1	2026Q2
Operating	-17.8	185	-17.1	-22.4	-17.6	-23.6	-18.1	-28.9	-28.8	-32.3	-45.9	-40.8	-47.7	-52.7	-44.5	445	-49.3	135	-57.4	-49.0	-48.9	-48.5	-43.0	-46.5	-46.1	-61.4	-62.8	-50.7	-55.0	-60.8	-49.0	-32.5	-41.7	-49.8	-34.2
Investing	-0.8	-180	-40.1	-47.0	42.5	-151	26.4	45.9	30.1	-125	-24.7	33.0	11.6	110	56.6	-69.0	-147	-12.1	-226	60.5	18.4	88.7	-21.8	17.0	18.1	-11.8	37.1	40.4	41.4	65.7	55.7	49.5	25.6	61.0	17.1
Financing	-0.01	-0.06	70.2	62.3	-1.28	170	-0.12	0.72	1.44	228	2.27	0.29	1.10	3.87	2.96	14.8	8.64	2.48	0.91	0.49	0.64	1.08	0.88	0	0.59	71.1	0.64	0	9.79	0	0.12	14.7	5.39	0.03	0.05
Cash at period end	32.5	37.4	48.9	41.9	65.5	61.0	69.2	87.0	89.6	161	92.5	85.0	50.0	111	126	517	329	455	172	184	154	196	132	102	74.6	72.5	47.5	37.2	33.0	38.0	44.8	76.5	65.8	77.0	59.9

Profitability

Quarterly · %

Operating margin -734.7% Net margin -692.5%

Gross, operating and net margin = the respective profit ÷ revenue.

Show table：Profitability

Item	2017Q4	2018Q1	2018Q2	2018Q3	2018Q4	2019Q1	2019Q2	2019Q3	2019Q4	2020Q1	2020Q2	2020Q3	2020Q4	2021Q1	2021Q2	2021Q3	2021Q4	2022Q1	2022Q2	2022Q3	2022Q4	2023Q1	2023Q2	2023Q3	2023Q4	2024Q1	2024Q2	2024Q3	2024Q4	2025Q1	2025Q2	2025Q3	2025Q4	2026Q1	2026Q2
Operating margin	-1137.8%	-194.2%	-172.1%	-258.6%	-207.9%	-370.4%	-392.5%	-1266.7%	-538.9%	-586.8%	-1469.7%	-910.4%	-1087.1%	-1280.7%	-842.3%	69.3%	-398.2%	-180.3%	11.9%	-321.5%	-383.9%	-302.8%	-6.4%	-555.3%	-312.4%	-275.0%	-302.4%	-315.7%	-13.4%	-1216.5%	-433.6%	-1153.6%	-634.4%	-2382.3%	-734.7%
Net margin	-1130.9%	-177.6%	-156.4%	-235.5%	-190.0%	-331.1%	-355.1%	-1177.2%	-508.7%	-558.1%	-1429.8%	-892.7%	-1075.2%	-1269.4%	-839.6%	69.4%	-397.4%	-182.3%	12.4%	-310.7%	-363.1%	-277.1%	2.5%	-488.3%	-272.8%	-227.0%	-256.4%	-275.2%	-3.8%	-1101.5%	-387.7%	-1063.4%	-597.5%	-2192.2%	-692.5%

Returns & leverage

Quarterly · %

ROE -385.1% ROA -42.1% Debt ratio 104.9%

ROE / ROA = trailing four-quarter net income ÷ average equity / total assets (annual mode: the year’s net income ÷ average of opening and closing). Not computed when the denominator is zero or negative.

Show table：Returns & leverage

Item	2017Q4	2018Q1	2018Q2	2018Q3	2018Q4	2019Q1	2019Q2	2019Q3	2019Q4	2020Q1	2020Q2	2020Q3	2020Q4	2021Q1	2021Q2	2021Q3	2021Q4	2022Q1	2022Q2	2022Q3	2022Q4	2023Q1	2023Q2	2023Q3	2023Q4	2024Q1	2024Q2	2024Q3	2024Q4	2025Q1	2025Q2	2025Q3	2025Q4	2026Q1	2026Q2
ROE	—	—	—	—	—	-60.4%	-86.0%	-135.8%	-216.5%	-38.6%	-49.1%	-63.8%	-82.3%	-65.3%	-78.6%	-10.2%	-12.8%	-11.6%	15.3%	-46.4%	-51.8%	-59.7%	-59.0%	-68.0%	-74.8%	-66.7%	-92.6%	-112.5%	-91.2%	-90.3%	-104.0%	-122.0%	-181.6%	-238.8%	-385.1%
ROA	—	—	—	—	-16.9%	-12.6%	-15.9%	-20.5%	-28.9%	-22.8%	-28.1%	-34.4%	-41.8%	-38.2%	-43.8%	-4.8%	-5.6%	-4.1%	5.6%	-16.1%	-16.6%	-15.8%	-17.9%	-18.7%	-18.5%	-17.4%	-25.1%	-26.7%	-21.8%	-23.6%	-24.9%	-25.3%	-37.5%	-38.7%	-42.1%
Debt ratio	—	—	—	—	63.3%	46.3%	48.5%	51.4%	53.8%	36.7%	37.9%	41.6%	45.2%	48.3%	53.5%	60.7%	63.1%	72.0%	67.6%	69.8%	72.8%	75.5%	72.3%	75.8%	78.4%	71.8%	73.6%	77.0%	72.9%	76.8%	80.0%	82.8%	89.5%	95.7%	104.9%

EPS

Quarterly · US$

EPS US$-0.21

Show table：EPS

Item	2017Q4	2018Q1	2018Q2	2018Q3	2018Q4	2019Q1	2019Q2	2019Q3	2019Q4	2020Q1	2020Q2	2020Q3	2020Q4	2021Q1	2021Q2	2021Q3	2021Q4	2022Q1	2022Q2	2022Q3	2022Q4	2023Q1	2023Q2	2023Q3	2023Q4	2024Q1	2024Q2	2024Q3	2024Q4	2025Q1	2025Q2	2025Q3	2025Q4	2026Q1	2026Q2
EPS（US$）	—	—	—	—	—	—	—	—	—	—	—	-0.67	-0.67	—	-0.69	1.49	-0.68	-0.54	0.12	-0.56	-0.64	-0.55	0.02	-0.53	-0.49	-0.38	-0.40	-0.43	-0.01	-0.41	-0.30	-0.34	-0.34	-0.21	-0.21

Revenue & profit

Year-to-date · In mn (USD)

Revenue 4.37 mn Net income -45.9 mn

Year-to-date = summed from the first quarter of the fiscal year; balance-sheet items are period-end balances.

Balance sheet

Year-to-date · In mn (USD)

Total assets 203 mn Total liabilities 213 mn

Equity = assets − liabilities. Balance-sheet figures are period-end balances, not cumulative.

Cash flow

Year-to-date · In mn (USD)

Operating -84.0 mn Investing 78.1 mn Financing 0.08 mn

Positive = cash in, negative = cash out.

Profitability

Year-to-date · %

Operating margin -1129.5% Net margin -1051.8%

Gross, operating and net margin = the respective profit ÷ revenue.

Returns & leverage

Year-to-date · %

ROE -385.1% ROA -42.1% Debt ratio 104.9%

EPS

Year-to-date · US$

EPS US$-0.42

Revenue & profit

Annual · In mn (USD)

Revenue 21.1 mn Net income -143 mn

Annual = sum of four quarters of a complete fiscal year (incomplete years are omitted); balance-sheet items are year-end balances.

Show table：Income statement

Item	2018	2019	2020	2021	2022	2023	2024	2025
Revenue	27.5	21.2	21.1	207	134	97.1	101	21.1
Operating income	-57.3	-114	-195	-37.4	-138	-152	-145	-156
Net income	-52.3	-105	-190	-36.3	-133	-130	-119	-143

Balance sheet

Annual · In mn (USD)

Total assets 293 mn Total liabilities 263 mn

Equity = assets − liabilities. Balance-sheet figures are period-end balances, not cumulative.

Show table：Balance sheet

Item	2018	2019	2020	2021	2022	2023	2024	2025
Current assets	293	357	422	750	726	566	425	266
Total assets	308	422	488	815	788	622	468	293
Current liabilities	48.0	62.0	68.1	140	93.8	178	125	69.5
Total liabilities	195	227	221	514	573	488	342	263
Equity	-97.4	195	268	301	214	134	127	30.6

Cash flow

Annual · In mn (USD)

Operating -184 mn Investing 197 mn Financing 20.2 mn

Positive = cash in, negative = cash out.

Show table：Cash flow statement

Item	2018	2019	2020	2021	2022	2023	2024	2025
Operating	127	-99.3	-167	299	-20.3	-184	-230	-184
Investing	-224	-48.9	-105	-49.7	-159	102	107	197
Financing	131	172	232	30.3	4.51	2.55	81.5	20.2
Cash at period end	65.5	89.6	50.0	329	154	74.6	33.0	65.8

Profitability

Annual · %

Operating margin -741.3% Net margin -679.2%

Gross, operating and net margin = the respective profit ÷ revenue.

Show table：Profitability

Item	2018	2019	2020	2021	2022	2023	2024	2025
Operating margin	-208.3%	-539.2%	-925.1%	-18.0%	-103.2%	-156.3%	-144.2%	-741.3%
Net margin	-189.9%	-496.6%	-901.6%	-17.5%	-99.8%	-134.3%	-118.4%	-679.2%

Returns & leverage

Annual · %

ROE -181.6% ROA -37.5% Debt ratio 89.5%

Show table：Returns & leverage

Item	2018	2019	2020	2021	2022	2023	2024	2025
ROE	—	-216.5%	-82.3%	-12.8%	-51.8%	-74.8%	-91.2%	-181.6%
ROA	-16.9%	-28.9%	-41.8%	-5.6%	-16.6%	-18.5%	-21.8%	-37.5%
Debt ratio	63.3%	53.8%	45.2%	63.1%	72.8%	78.4%	72.9%	89.5%

EPS

Annual · US$

EPS US$-1.39

Show table：EPS

Item	2018	2019	2020	2021	2022	2023	2024	2025
EPS（US$）	—	—	—	—	-1.62	-1.55	-1.22	-1.39

Source: SEC EDGAR (XBRL company facts)

Annual reports by year

	10-K
2025	Open full text →
2024	Open full text →
2023	Open full text →

10-K: annual report of a US domestic issuer. Filings are the original documents hosted on SEC EDGAR — this site neither mirrors nor edits them.

FAQ

Where can I read Alector, Inc. (ALEC) annual reports?

Every year in the table above links straight to the full text on SEC EDGAR. US annual reports are web pages (HTML) rather than PDFs, so you can read and search them in the browser without downloading anything. 3 filings are currently indexed.

What is the difference between a 10-K and a 20-F?

A 10-K is the annual report of a US domestic issuer, with sections fixed by law: Item 1 Business, Item 1A Risk Factors, Item 7 Management's Discussion and Analysis. A 20-F is filed by foreign private issuers — Taiwanese companies with US ADRs, such as TSMC, file 20-F rather than 10-K. A 40-F applies to Canadian issuers under the MJDS.

Are earnings call materials available here?

No. Earnings calls are not SEC filings, so US pages on this site cover annual reports only. Taiwan has a mandatory investor-conference disclosure regime, and those materials are indexed under Annual Reports.

Source: US Securities and Exchange Commission (SEC) EDGAR. This site indexes public filings and links to them; it hosts no copies, offers no investment advice, and makes no warranty as to timeliness or completeness.
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