I have a question - I've seen TikToks of people who buy rolls of coins from the bank and sort through them for rare imperfections then sell them on eBay. I've always wondered whether it would be possible to develop an automated system where a camera takes high res photos of the coins on a conveyor belt, compares to a DB of known imperfections and sets them aside?

Is anyone doing this? It's an interesting business model as the product is money so you'd only stand to make a profit never a loss.

Nobody that I know of is doing this, and see no reason why it wouldn't be possible from a technical standpoint. I think the only reason I can imagine NOT to do is that the ROI probably isn't that high in reality. Now, granted, I don't watch the coin TikToks because 95% of it is clickbait, exaggerate, etc. But my actual impression is that there simply isn't that much actually-valuable material out there hiding in bank rolls (despite what TikTok says).

Most of the people I know who do bank roll hunting and doing it because it's just kinda fun and there's a thrill when you find a silver quarter from 1964 (worth about $5) hiding in a roll of otherwise-normal quarters. But so much of the good stuff has already been plucked from circulation.

Having said that, nothing should stop a good hacker from doing something just for the hell of it :)

If there was a good ROI the banks would do it. It might be enough ROI living but it will be a lot of labor for a small income.

Tellers get first dibs

do you know why vendors take credit cards, square and applepay, even though those services charge several percent fees? part of it is for convenience for the customer, but another part is that shuttling cash around to the bank and back is time consuming, risky, and takes you away from running your business (let's say you are a breakfast place, you don't make your own cups and napkins or farm your own eggs and coffee either)

>product is money so you'd only stand to make a profit never a loss

you're grabbing the expense part of the business that everybody else is trying to shed. Let's talk also about time value of money. All the money that you've invested in cash is not making money passively as other investments do. Compared to putting the money in the stock market, you're losing 7% a year on this scheme, plus the expenses of running your business, and opportunity cost of not doing something else that generates income.

I did this for personal collections a while back and went through a lot of Canadian quarters to get one from each year and never even found the 1991 I was looking for which is somewhat rare. I guess if you do it full time or automate a bunch maybe you could make money, seems hard though.

That is beautiful!.

One of my favorite design elements is the Guilloche patterning on currency, along with the history behind the use of Guilloche as a form of anti-counterfeiting.

Your site is very simply visually appealing.

Also - I like to order $2 bills from the bank. You can order then, mine delivers them on tuesdays - and they give you a stack of brand new $2 sequentially serialized bills. They are great for tips and gifts.

100% agree! I often get folks asking if their $2 are valuable, and tell them exactly what you do -- no, alas, they're not worth more than $2, but they are super fun to leave as tips because people still get a kick out of 'em.

Very cool and super clean website! Talk about your infra please!

Thanks!!

Infra: I was hosted on Google Cloud for a while -- literally a single VM running Docker Compose, but I decided I wanted something a bit more flexible and interesting, so last month I switched everything over to Fly.io and I am incredibly happy with them. It's just so easy and fun to manage.

The retail site (rarity7.com) is just a small VM running a Crystal server process to handle web requests. Image hosting is all done on Cloudinary. My backend / inventory management / trading + research engine is a separate Crystal process in a separate VM. Both connect to a Fly Postgres DB. There's one other service which is a small python process on another VM which is doing inference on my regression model. That's super lightweight and I don't need any GPUs to do the inference (tabular data is nice like that).

Overall it's really nothing fancy and it works quite well. A few web-serving VMs and an inference service for my pricing model. I train/retrain the model a few times a year on a local box (my repurposed gaming rig running a 2080Ti).

That's neat and congrats! How long does it take to be part of the authorized dealers listed on the site?

I did it all in about 2-3 years. I was a big collector as a kid but didn't get back into it in a serious way until 2021. Becoming an authorized dealer is basically, fundamentally about building trust. The whole coin industry operates in a very old-school relationship-based trusted way. To become a member of most professional orgs or become an authorized dealer, you need to have 5-10 VERY solid references from other members or authorized dealers, and the only way to get those references is to be a part of the community, build trust, and build relationships by doing business with others (which means honoring your commitments and your word and writing good checks, etc.). In the end, you need to ask 5-10 people to personally vouch for you, so they'd better know you and actually trust you.

This is great, my brother is a history buff and a few years ago I bought him a Hadrian coin for his birthday. I'll look through this and see if I can find something else he'd be interested in, holidays are coming up and I'm always looking for nice gifts.

EDIT: is there any way I could set up an alert for when you add some non-US currency into stock?

That's awesome and a very thoughtful gift for him! Yes I'm planning on building alerting - BUT - I'm probably not going to expand beyond US-based stuff for the foreseeable future. It's just the niche I know and even though there's a big wide world out there, I haven't spun up my brain to learn about it all yet.

If there's any country in particular you're looking for, shoot me an email. I know a ton of other dealers in the business and I'd be happy to point you to someone who might have something he'd enjoy.

Cool project! I showed this to my 13 year old son who is a coin and bill collector; he loves it.

Awesome -- thanks! Tell your son to join the Instagram coin community if he hasn't done it already - there are tons of kids & adults on there and it's a real community that meets up regularly at coin shows, etc. Send me an email and I can give you a heads-up on some starter accounts to follow and get involved.

So let's say I have a few hundred silver dollars. Is this a tool to help me sort them, or does such a tool exist? Like take a picture and it identifies it, looks for common errors, and provides a base price estimate?

There really should be, but the fact is there isn't a tool that does this yet. It would not be deeply hard to build, but it would mean training a model which means getting good enough training data which means taking the time to actually do it. It hasn't been done because it requires someone who is deeply knowledgable about coins AND someone who knows how to train a model and build an app, and the fact is that intersection is pretty small (it's me and probably 20 other people? Give or take). This is very much on my long-term roadmap.

In the short term, the easiest way is to find someone who does this (eg me) and just email me some pictures. I'd be happy to tell you if you've got anything good. The old school neural net between my ears can assist.

(See profile for email).

That's fair. I have to imagine that there's a market for a product like that. My mind goes to auctioneers and estate sales. I know the local auctioneer would kill for a tool like that.

Something to keep in mind if you do build that: have a one time purchase or month long purchase option. When my wife's grandma died, we had to go through her coins looking for good ones. I would've killed for something like this but for a month.

Am curious how you handle trust.

E.g. someone says the delivery didn't come through. Or that the coin is not authentic.

Those are some expensive coins! So was curious.

Great question. Authenticity is easy - I mostly deal with certified coins, which means they’ve all been authenticated and guaranteed by a 3rd party service which stands behind their mark (they will pay you for the coin if they make a mistake, which does happen).

For shipping, that’s just pretty standard across most industries - I have shipping insurance and if USPS fails, they’ll pay for it. But losses happen and it’s just a matter of business (thankfully they’re rare).

The 3rd party service, do they require you to mail the actual coins to them before they authenticate?

Besides your love for the language and nobody telling you otherwise, why Crystal?

wow this is super cool stuff. I see the similarities between currencies and trading cards.

seems like you guys also have grading services

Yes! Very much so. And in fact, the grading services are owned by the same parent companies. NGC and PCGS are the big coin graders and I think their card graders are CGC and PSA respectively?

Are 1987 loonies rare?