Derek Maetzold reports multiple Rule 144 sales — CSTL (CSTL)

Rhea-AI Filing Summary

Derek Maetzold reported proposed sales of Common shares of CSTL under Rule 144, listing multiple transactions dated between 01/05/2026 and 03/18/2026.

The filing lists numerous individual dispositions by Mr. Maetzold and related trusts, with transaction entries showing share counts and dollar values for each trade, including a 23,179-share entry on 03/12/2026. The filing is a disclosure of proposed/resale transactions under Rule 144.

Insights

Securities Compliance Analyst

Rule 144 resale disclosures list many small-to-mid sized sales by a single reporting family.

The filing catalogs numerous share dispositions by Derek Maetzold and affiliated trusts across January–March 2026, each row showing share counts and proceeds. These entries are standard Rule 144 resale notices that document intended or proposed sales rather than company actions.

Timing and cash‑flow treatment are set by the reported trade dates and proceeds lines; subsequent filings or broker confirmations would show settlement details.

Equity Capital Markets Specialist

Multiple dated sale entries imply ongoing dispositions rather than a single block sale.

Entries include repeated trades of 1,339 shares on several January 2026 dates and larger entries such as 23,179 shares on 03/12/2026. The table-style listing is consistent with routine sell-through of previously acquired or issued shares.

Impact on free float depends on total outstanding shares, which are not provided in the excerpt; market impact cannot be assessed from these rows alone.

Form 144 Filer Information	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 144 NOTICE OF PROPOSED SALE OF SECURITIES PURSUANT TO RULE 144 UNDER THE SECURITIES ACT OF 1933
FORM 144

144: Filer Information

Filer CIK
Filer CCC
Is this a LIVE or TEST Filing?	LIVE TEST
Submission Contact Information
Name
Phone
E-Mail Address

144: Issuer Information

Name of Issuer

SEC File Number

Address of Issuer

Phone

Name of Person for Whose Account the Securities are To Be Sold

See the definition of "person" in paragraph (a) of Rule 144. Information is to be given not only as to the person for whose account the securities are to be sold but also as to all other persons included in that definition. In addition, information shall be given as to sales by all persons whose sales are required by paragraph (e) of Rule 144 to be aggregated with sales for the account of the person filing this notice.

Relationship to Issuer

144: Securities Information

Title of the Class of Securities To Be Sold	Name and Address of the Broker	Number of Shares or Other Units To Be Sold	Aggregate Market Value	Number of Shares or Other Units Outstanding	Approximate Date of Sale	Name the Securities Exchange
Common	Goldman Sachs & Co. LLC 200 West Street New York NY 10282	18180	449046	29731198	03/26/2026	NASD

Furnish the following information with respect to the acquisition of the securities to be sold and with respect to the payment of all or any part of the purchase price or other consideration therefor:

144: Securities To Be Sold

Title of the Class	Date you Acquired	Nature of Acquisition Transaction	Name of Person from Whom Acquired	Is this a Gift?	Date Donor Acquired	Amount of Securities Acquired	Date of Payment	Nature of Payment *
Common	10/29/2007	Acquired as gift	Derek Maetzold		10/29/2007	4071	10/29/2007	None
Common	10/29/2007	Acquired as gift	Derek Maetzold		10/29/2007	3459	10/29/2007	None
Common	10/29/2007	Acquired as gift	Derek Maetzold		10/29/2007	834	10/29/2007	None
Common	10/29/2007	Acquired as gift	Derek Maetzold		10/29/2007	834	10/29/2007	None
Common	10/29/2007	Acquired as gift	Derek Maetzold		10/29/2007	834	10/29/2007	None
Common	10/29/2007	Acquired as gift	Derek Maetzold		10/29/2007	834	10/29/2007	None
Common	11/12/2018	Acquired as compensation -- Stock Options	Issuer			7314	11/12/2018	Compensation -- Cashless exercise / same-day sale

* If the securities were purchased and full payment therefor was not made in cash at the time of purchase, explain in the table or in a note thereto the nature of the consideration given. If the consideration consisted of any note or other obligation, or if payment was made in installments describe the arrangement and state when the note or other obligation was discharged in full or the last installment paid.

Furnish the following information as to all securities of the issuer sold during the past 3 months by the person for whose account the securities are to be sold.

144: Securities Sold During The Past 3 Months

Name and Address of Seller	Title of Securities Sold	Date of Sale	Amount of Securities Sold	Gross Proceeds
Derek Maetzold 1500 W. Parkwood Ave Suite 400 Friendswood TX 77546	Common	01/05/2026	1339	50927.53
Derek Maetzold 1500 W. Parkwood Ave Suite 400 Friendswood TX 77546	Common	01/05/2026	1339	50917.89
Derek Maetzold 1500 W. Parkwood Ave Suite 400 Friendswood TX 77546	Common	01/06/2026	1339	53608.07
Derek Maetzold 1500 W. Parkwood Ave Suite 400 Friendswood TX 77546	Common	01/20/2026	1339	53446.85
Derek Maetzold 1500 W. Parkwood Ave Suite 400 Friendswood TX 77546	Common	01/20/2026	1339	53456.36
Derek Maetzold 1500 W. Parkwood Ave Suite 400 Friendswood TX 77546	Common	01/20/2026	1339	53588.52
Derek Maetzold 1500 W. Parkwood Ave Suite 400 Friendswood TX 77546	Common	02/03/2026	1339	53295.68
Derek Maetzold 1500 W. Parkwood Ave Suite 400 Friendswood TX 77546	Common	02/03/2026	1339	53300.23
Derek Maetzold 1500 W. Parkwood Ave Suite 400 Friendswood TX 77546	Common	02/03/2026	522	20932.2
Derek Maetzold 1500 W. Parkwood Ave Suite 400 Friendswood TX 77546	Common	02/04/2026	817	30986.44
The Maetzold 2018 Remainder Trust f/b/o Peter Douglas Maetzold 1500 W. Parkwood Ave Suite 400 Friendswood TX 77546	Common	03/11/2026	116	3046.66
The Maetzold 2018 Remainder Trust f/b/o John Derek Maetzold 1500 W. Parkwood Ave Suite 400 Friendswood TX 77546	Common	03/11/2026	116	3046.66
Derek Maetzold 2020 Irrevocable Trust dtd 12/04/2020 1500 W. Parkwood Ave Suite 400 Friendswood TX 77546	Common	03/11/2026	662	17328.25
Derek Maetzold 1500 W. Parkwood Ave Suite 400 Friendswood TX 77546	Common	03/11/2026	5408	140070.44
Derek Maetzold 1500 W. Parkwood Ave Suite 400 Friendswood TX 77546	Common	03/11/2026	3587	93891.88
The Maetzold 2018 Remainder Trust f/b/o Emily Carol Kirk 1500 W. Parkwood Ave Suite 400 Friendswood TX 77546	Common	03/11/2026	199	5208.94
Derek Maetzold 2020 Irrevocable Trust dtd 12/04/2020 1500 W. Parkwood Ave Suite 400 Friendswood TX 77546	Common	03/11/2026	498	13079.62
Derek Maetzold 1500 W. Parkwood Ave Suite 400 Friendswood TX 77546	Common	03/11/2026	5676	147027.7
Derek Maetzold 1500 W. Parkwood Ave Suite 400 Friendswood TX 77546	Common	03/11/2026	2639	69311.49
The Maetzold Descendants 2020 Trust dtd 12/4/2020 1500 W. Parkwood Ave Suite 400 Friendswood TX 77546	Common	03/11/2026	621	16310.13
The Maetzold 2018 Remainder Trust f/b/o Emily Carol Kirk 1500 W. Parkwood Ave Suite 400 Friendswood TX 77546	Common	03/11/2026	83	2179.94
The Maetzold 2018 Remainder Trust f/b/o Peter Douglas Maetzold 1500 W. Parkwood Ave Suite 400 Friendswood TX 77546	Common	03/11/2026	163	4266.62
The Maetzold 2018 Remainder Trust f/b/o Hannah Elizabeth Maetzold 1500 W. Parkwood Ave Suite 400 Friendswood TX 77546	Common	03/11/2026	166	4345.15
The Maetzold Descendants 2020 Trust dtd 12/4/2020 1500 W. Parkwood Ave Suite 400 Friendswood TX 77546	Common	03/11/2026	736	19265.24
The Maetzold 2018 Remainder Trust f/b/o Hannah Elizabeth Maetzold 1500 W. Parkwood Ave Suite 400 Friendswood TX 77546	Common	03/11/2026	113	2967.87
The Maetzold 2018 Remainder Trust f/b/o John Derek Maetzold 1500 W. Parkwood Ave Suite 400 Friendswood TX 77546	Common	03/11/2026	163	4266.62
Derek Maetzold 1500 W. Parkwood Ave Suite 400 Friendswood TX 77546	Common	03/12/2026	23179	584548.88
Derek Maetzold 1500 W. Parkwood Ave Suite 400 Friendswood TX 77546	Common	03/13/2026	13204	335209.95
Derek Maetzold 1500 W. Parkwood Ave Suite 400 Friendswood TX 77546	Common	03/16/2026	17575	455350.68
Derek Maetzold 1500 W. Parkwood Ave Suite 400 Friendswood TX 77546	Common	03/17/2026	18650	482441.93
Derek Maetzold 1500 W. Parkwood Ave Suite 400 Friendswood TX 77546	Common	03/18/2026	650	16461.71

144: Remarks and Signature

Remarks

Date of Notice

Date of Plan Adoption or Giving of Instruction, If Relying on Rule 10b5-1

ATTENTION:

The person for whose account the securities to which this notice relates are to be sold hereby represents by signing this notice that he does not know any material adverse information in regard to the current and prospective operations of the Issuer of the securities to be sold which has not been publicly disclosed. If such person has adopted a written trading plan or given trading instructions to satisfy Rule 10b5-1 under the Exchange Act, by signing the form and indicating the date that the plan was adopted or the instruction given, that person makes such representation as of the plan adoption or instruction date.

Signature

ATTENTION: Intentional misstatements or omission of facts constitute Federal Criminal Violations (See 18 U.S.C. 1001)

FAQ

What transactions does the CSTL Form 144 by Derek Maetzold show?

The Form 144 lists multiple proposed sales of Common shares dated between 01/05/2026 and 03/18/2026. Each line shows the selling party, trade date, number of shares, and the gross dollar amount for that disposition.

How many shares were in the largest sale reported in the filing?

The largest single entry shown is 23,179 shares reported on 03/12/2026. The filing presents this as a listed disposition line with an associated gross dollar figure; it does not aggregate totals across entries.

Who are the selling parties listed in the CSTL filing?

Selling parties include Derek Maetzold individually and several related trusts (for example, the Maetzold 2018 Remainder Trust and Derek Maetzold 2020 Irrevocable Trust). Each party appears with discrete share-sale entries and dollar amounts.

Do the Form 144 entries state proceeds treatment or buyer identity?

Each row shows a gross dollar amount for the trade, but the excerpt does not specify buyer identities or whether proceeds go to the issuer or selling holders. The lines reflect reported sale proceeds per trade date as displayed.

Are these filings evidence of new insider compensation or option exercises?

The listed dispositions are resale/sale entries. The excerpt includes prior acquisition notes (e.g., "Acquired as gift" and "Compensation -- Stock Options" acquisition dates) but the current Form 144 rows record sales, not new grants or exercises.