Pass Perfect is a securities-education publisher known for the principal and operations exams: eBook plus test bank, chapter video lectures, multi-level assessments, and optional live virtual review, with seven-month access. Trelos is a complete daily study system built on retention: it teaches every concept, drills it in FINRA's phrasing, and schedules review so near-identical supervisory rules stay distinct through test day. It does not include an eBook, live review, or full-length timed finals.
Per current third-party listings, Pass Perfect's Series 24 packages run $390 (eBook + test bank), $546 (eBook + live virtual review), and $598 (complete bundle), all with seven-month access; its Series 99 package is a single $155 tier (eBook + test bank) on the same seven-month window. Packages include chapter video lectures and animated videos aligned to the eBook, with assessments at topic, chapter, mid-term, and final level. Pass Perfect does not publish its question counts. Current packages are on Pass Perfect's site.
Trelos is a mobile-first retention engine with a separate track per exam: Series 24, 180 questions across 30 concepts; Series 99, 180 across 30; Series 26, 180 across 30; Series 9/10, 180 across 30, each organized by the exam's official functions. Every concept: guess first, short lesson, practice, scheduled review, confident mistakes returning first. Standard multiple choice with an explanation on every answer. Each track covers its exam's full outline on its own; Trelos does not include an eBook, video, live review, or full-length timed finals.
| Trelos | Pass Perfect | |
|---|---|---|
| Core model | Retention engine: guess → learn → drill → scheduled review | eBook + test bank + video, with optional live review |
| Instruction | Text lessons, one concept at a time | Chapter video lectures; live virtual review on upper tiers |
| Full-length timed finals | No — short timed section tests and a 14-question mixed mock | Yes — chapter, mid-term, and final exams |
| Spaced review | Automatic, built into every concept | Not a stated feature |
| Question count | Published per track | Not published |
| Access | 12 months, one payment | 7 months |
| Price | Free to start · from $14 launch price (from $29 after Nov 30) · pass guarantee | Series 24 $390–$598; Series 99 $155 |
| Best for | Keeping approval timelines and rule pairs producible | Textbook-style study with video and finals |
Choose Pass Perfect if you study best from a full textbook with chapter structure, you want live review, or you need staged practice exams through a final — none of which Trelos includes.
Choose Trelos if your failure mode is the principal exams' signature trap: supervision rules that look identical across contexts, deadlines that blur, who-approves-what-within-how-many-days. Precise recall under FINRA's phrasing is what spaced review protects, a few minutes at a time around a working day.
Pass Perfect's textbook model suits candidates who want to read the whole domain in order. The Series 24 and 9/10 are breadth exams, though, and breadth is exactly what decays between a chapter read in week one and an exam in week eight. Trelos keeps every concept on a return schedule so none of them goes cold. Its first topics are free with no sign-up to start; one payment buys 12 months, extended free if you meet the guarantee's conditions and don't pass.
Pass guarantee: learn every concept in your track and keep up your scheduled reviews, and if you still don't pass, your access is extended free — three more months per attempt — until you do. It's an extension, not a refund.
Preparing for a principal or operations exam? Pick your track:
No credit card. Feel the retention engine work in your first session.
Related: Series 24 Exam Guide · Series 99 Exam Guide · Series 9/10 Exam Guide · Free Series 24 Practice Questions, or browse all Trelos exam guides.
How Trelos works · why guessing first, spaced review and mixed practice make it stick.
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