Be sure of what you're buying. Stay sure while you hold it.

Stress test a stock before you buy. Write down why you bought. penKeep keeps checking that your reason still holds — and tells you when it's tested.

Your broker records the trade. penKeep remembers the decision — your notes, the relevant filings and news, and what you did next, kept together in one place.

Free stress test — before you buy

Search a company and see the strongest case against owning it. One test is free.

NVDANVIDIA
NEEDS REVIEW
AUG 28 · EVIDENCE
Blackwell shipments slipping into Q4. Gross margin came in at 74.6%, below the 76.4% everyone expected. Google and Amazon both stepping up their own chip programs.
WHAT WOULD CHANGE YOUR MIND · WRITTEN JAN 9
“If the cloud companies stop spending on AI chips, or Nvidia loses the developer ecosystem, I'm out.”
Reason still holds →Reason no longer holds →
Before you buy

Be sure of what you're buying.

Run one free stress test. See the strongest case against owning the stock, the numbers behind it, and what would have to stay true for the purchase to make sense.

Run a free stress test →
While you hold

Know your reason still holds.

Write down why you bought. penKeep checks filings, news, and earnings against your reason, and asks you to look only when something actually tests it.

Start your record →
The missing record

The market remembers the price.
It does not remember your reasoning.

Six months later, every decision has a neat explanation. The original uncertainty, the warning you dismissed, and the condition you promised to watch have disappeared.

A gain can hide a poor decision. A loss does not always mean the thinking was bad. Without the original notes, it is hard to learn much from either one.

Try it

Write one reason you own a stock.
See the facts penKeep would check.

Try with →auto-cycling
Your thesis · NVDAlive demo
edit me · or pick a starter →
penKeep would track
Healthy · 84/100
AI chip demandCustomer retention
Checks created from your reason
Large cloud companies' AI spending
·NVIDIA data-centre revenue growth
·Management comments on customer demand
How it works

Write it down. Keep watch. That is the whole thing.

01
Record the decision
Write why you own it and what would change your mind. Do it now, while you still remember what you were thinking.
02
Watch the evidence
penKeep reads the earnings, filings and news, then ignores everything that does not touch a condition you put on record.
03
Revisit the call
If one of those conditions changes, penKeep shows you what you wrote and what happened. You decide what to do next.
At the decision point

Your original decision,
returned with the evidence.

Not an AI recommendation. Just the condition you wrote, the new information, and the decision you made afterward, kept together.

Evidence
Your reason
You decide
On record
New evidence
Your condition
You decide
Decision saved
TSLATesla
live
Review now

Tesla delivered 8.4% fewer vehicles than a year earlier. Seven of nine analysts called the robotaxi event underwhelming.

click to pause · auto-cycling

A real story

One decision.
Eight months.

One TSLA decision, followed from the original belief to its first real test. The record preserves what the investor knew, when the evidence changed, and the call made next.

T
TSLA · Tesla
Bought Mar 2024 · Mar 12, 2024
✓ reason holds
What you wrote · Mar 12
“I expect vehicle sales to grow and robotaxis to become a meaningful source of revenue.”
Mar 12 · Bought TSLA
I expect vehicle sales to grow and robotaxis to become a meaningful source of revenue.

Re-created from public coverage of TSLA, Mar–Oct 2024. Not financial advice.

What makes the record useful

A decision record , not another investing feed.

Not just alerts
An alert tells you what happened today. penKeep also shows what you wrote before it happened and keeps the decision you made next.
Not a social feed
There is no crowd to perform for and no hot-stock loop. This is a private record of the portfolio and decisions that are actually yours.
No buy or sell calls
penKeep shows you the notes and the new information. It does not make the decision for you.
Not daily engagement
Most days the record stays quiet. It returns only when evidence matches a condition you wrote or an earlier decision is ready for review.
The part you didn't write down
The thing that sinks a stock is usually the one you'd have felt silly writing down.
penKeep also checks for major customer, competitor, regulatory and management changes that could affect your reason, even when you did not name them. If one matters, it shows you the source and the part of your reason that may need another look.
Before the decision
Make the bear case part of the record.
Before you buy, run the ticker through the counter-thesis . penKeep gives you the strongest argument against it, risks you may have missed, and specific conditions to watch.
After a year
Build a private track record of how you decide.
You can look back at which assumptions held, which warnings you ignored, and what you were thinking when you chose to hold, trim, or sell.
After each hold, trim or exit decision, penKeep records what happened next. Quarterly reviews show which warnings you acted on, which you dismissed, and whether those calls held up.
Questions

Is this financial advice?

No. penKeep never tells you to buy, hold or sell. It shows you what is happening to the reasons you wrote down, and every decision stays yours.

Do you connect to my brokerage?

You can connect it read-only to track positions, or just add your holdings by hand. We never place trades and never touch your money.

How is this different from another alert app?

Alerts disappear after telling you what happened. penKeep ties evidence to the belief you recorded, captures the decision you made, and returns it later when the outcome can be reviewed.

Will I get spammed with alerts?

No. Most weeks you will hear from us once, in the Sunday digest. We only send a real-time alert when something directly tests one of your exit conditions.

Your notes stay private · free to start

Put your first decision
on the record.

Start with a position you already own, or run the bear case before the next one.

Record your first decision →Stress-test a ticker →