Status: Killed · August 2020

Robintrack

The leaderboard that showed Wall Street every degen's cards — until Robinhood pulled the plug.

A 23-year-old student used Robinhood's own open API to reveal, hour by hour, how many users held each stock. The pros noticed. Then the API went dark.

Read the storySee the leaderboard
300K+
visitors / month
1 hr
update cadence
$0
build budget
Aug 2020
shut down
AAPL▲ +1.24%TSLA▲ +4.87%F▼ -0.42%GE▲ +2.10%AAL▼ -3.55%CCL▲ +6.02%DIS▲ +0.88%GPRO▼ -1.19%NKLA▲ +11.4%SNAP▲ +2.33%PLUG▼ -2.77%MSFT▲ +0.51%NIO▲ +8.91%AMD▲ +3.04%AAPL▲ +1.24%TSLA▲ +4.87%F▼ -0.42%GE▲ +2.10%AAL▼ -3.55%CCL▲ +6.02%DIS▲ +0.88%GPRO▼ -1.19%NKLA▲ +11.4%SNAP▲ +2.33%PLUG▼ -2.77%MSFT▲ +0.51%NIO▲ +8.91%AMD▲ +3.04%
01 — The side project

A college kid built the mirror Wall Street didn't know it wanted

Casey Primozic was 23. What started as a college side project quietly became a minor obsession of Wall Street. He plugged into Robinhood's own open API and built something the brokerage never advertised: a live, hourly leaderboard of exactly how many Robinhood users held each stock.

The site pulled in over 300,000 visitors a month. Hedge funds and financial firms started reaching out — some wanting to build algorithms directly on his data.

The pros were trading against Robinhood users — using Robinhood's own data.
02 — The data

Most-held stocks on Robinhood

A recreation of the view that made the site famous — number of unique holders, once updated hourly.

Archived snapshot · not live — the API was killed in Aug 2020
TickerHolders24h
F0+3.4%
AAL0+8.9%
GE0+1.2%
DIS0+2.1%
CCL0+12.6%
TSLA0+4.8%
AAPL0+0.7%
GPRO0-1.9%
SNAP0+2.3%
NKLA0+24.7%

Frozen data · illustrative figures · original Robinhood API discontinued Aug 2020

03 — The timeline

From side project to shutdown

2018

A dorm-room experiment

Casey Primozic, a student, starts pulling Robinhood's open API for fun and charts how many users hold each stock.

2019

Wall Street starts watching

Traders realize the data is a real-time X-ray of retail sentiment. Robintrack becomes required reading on trading desks.

Early 2020

The retail boom

Lockdowns and stimulus checks send millions of new users to Robinhood. Robintrack traffic explodes past 300K visitors a month.

Mid 2020

The funds come knocking

Hedge funds and financial firms reach out — some wanting to build algorithms directly on the holder data.

August 2020

The plug is pulled

Robinhood cuts off the API, citing "other people" using the data in ways it couldn't monitor or control. The site freezes.

04 — The kill switch
Robinhood said “other people” were using the data in ways they couldn't monitor or control — potentially at the expense of their own users.

So they cut the API. No more hourly updates. No more window into what retail was holding. The tool that made Robinhood's crowd legible to the pros went dark overnight — and stayed that way.

05 — The tombstone

robintrack.net still stands

R · I · P
Robintrack
2018 — 2020

“The site has been frozen ever since. The kid who showed Wall Street every degen's cards — until Robinhood pulled the plug.”

The domain still exists as a tombstone — a frozen snapshot of the moment retail trading became a spectator sport.