- The underground exchange always trades two vials of dream dust for illegal goods.
- Store contraband in the hidden 2x2 space behind the poster to avoid risk.
- Mix legal items with dream dust to hit the wholesale bonus safely.
- B4 buys uncategorized junk and old documents before the landlord arrives.
- Black market trades build revolution reputation, distinct from security or upper levels.
What Is the Underground Exchange?
The underground exchange is Probably Stolen's black market trading channel, a reliable way to convert certain contraband into other illegal goods without relying on walk-in customers. Its most consistent behavior is the dream dust trade: it will always exchange two vials of dream dust for something illegal. This makes it a dependable pipeline for players who want to stockpile contraband without waiting for random black market visitors.
Black market contacts are tied to the revolution faction, and identifying who you are actually trading with matters. Every faction in the game has its own text color, so check the background of the dialogue text rather than the customer's clothing. Security is red, the black market signals revolution affiliation, and lower level citizens usually appear in a gray tone.
Video Highlights:
- The underground exchange always converts two dream dust vials into illegal items
- The hidden 2x2 space behind the poster fits one keycard or four dream dust vials
- Mixing contraband into legal trades can trigger the wholesale bonus
- Faction identity is revealed by text color, not appearance
When a visitor arrives and you are unsure of their faction, look at the dialogue background color. Trading with the wrong faction unknowingly can shift your standing in ways you did not intend, especially when juggling security reputation alongside black market deals.
Contraband Storage and the Hidden Compartment
The single most important discovery for any contraband operation is the smuggler's compartment behind the poster. There is a 2x2 hidden space that fits either one keycard or four vials of dream dust. This gives you a low-risk reserve of illegal goods that regular inspections are unlikely to touch.
| Storage Method | Capacity | Risk Level | Best Use |
|---|---|---|---|
| Hidden poster space | 1 keycard or 4 dream dust vials | Very low | Emergency contraband reserve |
| Extended storage bay | 17x10 (170 squares) | Moderate | Bulk legal inventory |
| Expanded machine bay | 14x11 (154 squares) | Moderate | Machines and most items |
| Open shop display | Varies | High | Attracting specific customers |
The four-vial capacity of the poster compartment aligns perfectly with common trade offers. Many incoming trades combine four vials of dream dust with fully legal items, meaning accepting those trades earns the wholesale bonus while the underground exchange stands ready to convert your spare vials into other illegal stock.
Keeping contraband in general storage rather than the hidden compartment exposes you during security checks. Maintaining good security standing, even while dabbling in the black market, reduces the chance your store gets targeted for controls.
Step-by-Step: Running a Dream Dust Pipeline
Accept mixed trades
Take trades that bundle four dream dust vials with legal items to earn the wholesale bonus on otherwise ordinary deals.
Bank vials behind the poster
Store up to four dream dust vials in the hidden 2x2 compartment so they stay off the books between exchanges.
Convert through the underground exchange
Feed two vials at a time into the exchange, which always returns illegal goods in return.
Balance faction standing
Offset black market activity by building security reputation, for example via the alarm transmitter module at one point per night.
The dream dust pipeline works best when paired with high-value legal display stock. Attracting wealthy wholesale buyers with premium labeled goods keeps credits flowing while your contraband side business matures quietly.
Managing Risk: Black Market vs Security
Running an underground exchange operation means walking a line between revolution-leaning profits and security-faction heat. The alarm system is an early purchase worth considering: it prevents theft based on your performance stat, and adding the alarm transmitter module (100 credits at Dr. Jackson) grants one security reputation per night at the cost of 50% efficiency, which a few efficiency modules can offset.
Alarm System
- Prevents store theft
- Scales with performance stat
- Supports reputation building
Alarm Transmitter Module
- +1 security rep per night
- Costs 50% efficiency
- Offsets black market heat
Joe Wild's Services
- Recovers stolen goods
- Enables store upgrades
- Pays for itself long-term
No alarm setup is fully bulletproof without extensive modding, so Joe Wild's recovery service remains a worthwhile backup. His upgrades frequently return more value than his fee costs.
Selling Junk and Funding the Operation
Uncategorized items and documents cannot be sold through regular trades, but B4 accepts all of them before the landlord's weekly visit. Appraisal guides, the water trading manual, spot-the-augs info sheets, and duplicate magnifying glasses all hold hidden value. Clearing them out also frees equipment space.
| Sellable Junk | Buyer | Notes |
|---|---|---|
| Dream dust vials (pair) | Underground exchange | Always converts to illegal goods |
| Old documents and manuals | B4 | Sell before landlord day |
| Duplicate magnifying glasses | B4 | Keep only one |
| Material-category items | Dr. Jackson | Guaranteed sale, 15% retail markup |
| Mouse traps (spare) | B4 | No regular profitable trade exists |
Dr. Jackson always buys anything in the material category, including metal ingots smelted from GP Mining ore. Prices still shift with in-game events, so sell during material shortages for maximum return.
Black Market Milestones:
- Discover the hidden 2x2 poster compartment
- Complete first underground exchange trade
- Trigger a wholesale bonus with mixed dream dust trade
- Reach positive security standing with alarm transmitter
- Clear all junk with B4 before landlord day
FAQ
Q: What does the underground exchange trade in Probably Stolen?
The underground exchange will always exchange two vials of dream dust for illegal goods, making it a reliable conversion channel for contraband stockpiling.
Q: Where can I safely store contraband?
There is a hidden 2x2 space behind the poster in your shop. It fits one keycard or four vials of dream dust, providing a low-risk smuggler's stash.
Q: Can I profit from dream dust trades with legal items?
Yes. Trades that bundle four dream dust vials with legal items can trigger the wholesale bonus, and spare vials can then be converted through the underground exchange.
Q: How do I reduce security attention while trading on the black market?
Build security standing with the alarm transmitter module for one reputation per night, and keep Joe Wild's services active in case anything is stolen from your store.