Many commercial MSJs are lost not because the law is against you but because the expert declaration doesn't meet the CCP § 437c(d) threshold -- personal knowledge, admissible, setting forth specific facts. Shows what an inadequate expert declaration looks like at the MSJ stage and what the court does with it.

How to Use — and Attack — Expert Declarations at the California Fraud MSJ

Summary judgment in a California commercial fraud case is often decided not on the merits of the alleged misrepresentation but on the admissibility and sufficiency of the damages declaration. A plaintiff who survives demurrer but arrives at the MSJ stage without a declaration that survives evidentiary scrutiny does not have a triable issue on damages. The motion is granted. The same dynamic runs the other direction: a well-constructed expert declaration can shift the Aguilar burden onto the plaintiff and force a response the plaintiff cannot make. The rules governing this are not intuitive, and the most common mistakes — bare conclusory opinions, sham rehabilitations of deposition concessions, and incomplete methodologies — are avoidable.

The Expert Declaration at MSJ

What the Law Requires

The statutory standard is a three-part test. A declaration supporting or opposing a motion for summary judgment "shall be made by a person having personal knowledge of the matter, shall set forth admissible evidence, and shall show affirmatively that the witness is competent to testify to the matters stated therein." Code of Civil Procedure section 437c(d). For an expert, competence is not assumed — it must be established by the declaration itself, with qualifications stated specifically enough to demonstrate subject-matter expertise.

The opinion must also show its work. A bare conclusion ("in my opinion, plaintiff's damages are $X") without disclosed methodology is subject to exclusion as speculative. The California Supreme Court confirmed the trial court's gatekeeping role in Sargon Enterprises, Inc. v. University of Southern California (2012) 55 Cal.4th 747, 770–771: courts exclude expert opinions based on unreliable methodology or speculative assumptions, even where the declarant has impressive credentials. Post-Sargon, a foundation objection that specifically challenges the methodology — not just credentials — is the right tool.

One additional trap: a statement made "on information and belief" is not based on personal knowledge and is not admissible at the MSJ stage. Bowden v. Robinson (1977) 67 Cal.App.3d 705, 718. Percipient witnesses who state what happened on information and belief are stricken on objection.

What the Corpus Shows

The Aguilar burden-shifting framework governs every California MSJ. Aguilar v. Atlantic Richfield Co. (2001) 25 Cal.4th 826, 855. The moving party can shift burden in two ways. Path A: present affirmative expert evidence negating a required element — for example, a defense expert establishing that the plaintiff's claimed damages do not flow from the alleged misrepresentation, or that actual value at the transaction date was equal to or greater than the represented value. Path B: show that the plaintiff's discovery record is factually devoid of admissible evidence on a required element, without producing your own expert at all. Where the plaintiff's interrogatory responses on damages are conclusory and their document production reveals no damages calculation, that is a factually-devoid showing under Path B.

In fraud cases specifically, the default damages measure is out-of-pocket loss: the difference between the actual value of what was given and the actual value of what was received. Civil Code section 3343. Establishing that requires evidence of actual value at the time of the transaction — not the plaintiff's subjective expectation, not the value today. Without a damages expert, there is typically no triable issue on this element.

Where lost profits are claimed, the standard is reasonable certainty. Berge v. International Harvester Co. (1983) 142 Cal.App.3d 152, 161. The expert must tie the lost-profits calculation to a demonstrable pre-fraud baseline and explain why the fraud — rather than market conditions, business decisions, or third-party factors — caused the loss. A lost-profits opinion that does not account for alternative causation is speculative and excludable under Sargon. Wiz Technology, Inc. v. Coopers & Lybrand (2003) 106 Cal.App.4th 1, 11 confirms that a conclusory expert opinion is insufficient to create a triable issue even if the declarant is qualified.

What Counsel Does

If you are the moving party:

Before filing, serve targeted discovery aimed at the plaintiff's damages theory: Form Interrogatory 20.8 (damages computation) and specially prepared interrogatories asking for every fact and document supporting each line item of damages. If the responses are conclusory, that is your Path B foundation.
If you use a defense expert to negate damages (Path A), the declaration must apply an explicit methodology to actual values at the transaction date. The goal is to establish that the plaintiff's damages are zero, de minimis, or traceable to a cause other than the alleged misrepresentation.
File written evidentiary objections to the plaintiff's expert declaration with your reply, not with the opening motion. Objections filed before seeing the opposition are premature. The deadline is 11 days before the hearing under California Rules of Court, rule 3.1354.
Lead your objections with Sargon: speculative methodology and failure to account for alternative causation. Pair that with Wiz Technology: conclusory opinion insufficient to create a triable issue. If both objections are sustained, the plaintiff is left with no admissible damages evidence.
Depose the plaintiff's expert before the MSJ briefing closes. Admissions about assumptions, data limitations, or methodological choices become the baseline against which the subsequent declaration is measured.

If you are the opposing party:

Designate a damages expert before the opposition deadline. Do not file without one if the motion attacks damages.
The expert declaration must (a) state qualifications specifically, not generically; (b) identify every document reviewed; (c) apply an explicit methodology for calculating actual value at the transaction date or for establishing the pre-fraud baseline for lost profits; (d) connect each damages line item to the specific misrepresentation alleged; and (e) address and distinguish alternative causation.
Prepare the expert for deposition before the MSJ issues if possible. An expert who is deposed after the motion is filed may be ambushed on the specific evidentiary gaps the motion identifies. Once the expert testifies to a methodology at deposition, that testimony is the baseline — a subsequent declaration that reverses deposition testimony without a disclosed methodological correction is a sham under D'Amico v. Board of Medical Examiners (1974) 11 Cal.3d 1, 21–22, and will be excluded.
To inoculate against Sargon objections: have the expert specifically state that the methodology is one customarily used by experts in the field, acknowledge the alternative explanations the defense is likely to raise, and explain why those alternatives do not account for the loss. The more work the declaration shows, the harder it is to strike as conclusory.
If the deposition of your expert goes badly — concessions on assumptions or methodology — the declaration cannot silently reverse those concessions. Either disclose the methodological change explicitly in the declaration or file a supplemental expert report with the new analysis disclosed.

This article is for educational purposes only and is not legal advice. All frameworks and sample language should be reviewed by a licensed attorney and adapted to your particular client, case, and situation.