EXA CORPORATION Burlington, MA 01803

Exhibit 4.26

EXA CORPORATION

00 Xxxxxxx Xxxxx

Xxxxxxxxxx, XX 00000

April 5, 0000

XXX LLC

Fidelity Ventures Limited

InfoTech Fund I LLC

00 Xxxxxxxxxx Xxxxxx

Xxxxxx, XX 00000

Boston Capital Ventures, III, Limited Partnership

Boston Capital Partners, IV, Limited Partnership

00 Xxxxx Xxxxxx

Xxxxxx, XX 00000

Attention: Xxxx X. Xxxxx and Xxxx Xxxxxxx

Re: Amendment No. 1 to Agreement for Participation in Initial Public Offering

Gentlemen:

Reference is made to that certain Agreement for Participation in Initial Public Offering, dated as of August 3, 2011 (the “Agreement”) by and between Exa Corporation (“Exa”), FMR LLC, Fidelity Ventures Limited (“FVL”), InfoTech Fund I LLC, as successor to Fidelity Investors Limited Partnership (“FILP” and collectively with FMR LLC and FVL, the “FMR Entities”) and Boston Capital Ventures, III, Limited Partnership and Boston Capital Partners, IV, Limited Partnership (collectively the “BCV Entities”).

At the request of Exa and Stifel and to facilitate the IPO, the FMR Entities and the BCV Entities, along with certain other shareholders of Exa, have agreed to extend the termination date of the Amendment, Consent and Waiver and the Lock-up Agreements described in the Agreement to June 30, 2012.

In consideration of the foregoing, and other good and valuable consideration, the sufficiency of which is hereby acknowledged, the undersigned agree as follows:

1. Section 8 of the Agreement shall be deleted in its entirety and replaced with the following:

This Agreement shall expire and become null and void in the event that an underwriting agreement with respect to Exa’s initial public offering shall not have been executed by June 30, 2012.

2. Except as expressly amended by this Amendment, all other terms and conditions of the Agreement shall remain in full force and effect without modification. Upon the effectiveness of this Amendment, each reference in the Agreement to “this Agreement,” “hereunder,” “herein,” or other words of like import shall mean and be a reference to the Agreement as amended hereby.

To confirm that this letter sets forth our agreement, kindly execute a copy of this letter where indicated below and return it to me.

*** Remainder of Page Intentionally Left Blank ***

We appreciate the continued support of the FMR Entities and the BCV Entities for Exa and the IPO process.

Sincerely,

EXA CORPORATION

/s/ Xxxxxxx X. Xxxxxxx

Xxxxxxx Xxxxxxx

Chief Executive Officer

cc:		Xxxx X. Xxxxxxxxx, Xx., Esq.
		Xxxxxx X. Xxxxx, Xx., Esq.
		Xxxxx Xxxxxxx, Esq.
		Xxxx Xxxxxxxxxx, Esq.
		Xxxx Xxxxxxxx, Esq.

FMR LLC
By		/s/ Xxxxxx X. Xxxxxxxxx
FIDELITY VENTURES LIMITED
By:		Fidelity Capital Associates, Inc. Its Managing General Partner
By		/s/ Xxxx X. Xxxxx

INFOTECH FUND I LLC
By:		Northern Neck Investors LLC
		Its Manager
By		/s/ Xxxx X. Xxxxx
BOSTON CAPITAL VENTURES III, LIMITED PARTNERSHIP
By:		/s/ Johan von der Xxxxx
BOSTON CAPITAL VENTURES IV, LIMITED PARTNERSHIP
By:		/s/ Xxxx X. Xxxxxxx, III