The Money Train series from Relax Gaming has developed a near-cult following among high-volatility slot players, and Money Train 4 is the most mechanically complex entry yet. The Bonus Buy isn’t just a shortcut here — it’s a strategy tool, because the game’s tiered buy options let you choose exactly how much firepower you want to start with.
This is a slot that demands understanding before you fund it. The 150,000x maximum win is one of the highest theoretical ceilings in the industry, but reaching it requires the right combination of persistent symbols. Here’s exactly how the buy system works, what each tier gets you, and where UK players can access it away from UKGC restrictions.
Money Train 4 Bonus Buy Overview
| Stat | Detail |
|---|---|
| Provider | Relax Gaming |
| RTP | 96.1%–97% (buy tier dependent) |
| Volatility | Extreme |
| Max Win | 150,000x stake |
| Bonus Buy Cost | 20x–500x stake (multiple tiers) |
| Min Bet | £0.10 |
| Max Bet | £20 |
Money Train 4 launched as the latest instalment in Relax Gaming’s flagship series, building on the Money Cart bonus mechanics that made the franchise famous. The 4×5 reel layout is deceptively simple — it’s what happens inside the Money Cart Bonus that defines this game completely.
The 150,000x max win sits alongside San Quentin as one of the most extreme figures in modern slots. That ceiling is only reachable through a specific convergence of persistent symbol effects, and the Bonus Buy is how serious players engineer their starting conditions.
The Tiered RTP System
One of the genuinely interesting things about Money Train 4 is that the RTP isn’t fixed — it shifts between 96.1% and 97% depending on which buy tier you select. This is notable because it inverts the usual logic: spending more on a higher buy tier actually gives you better return rates, not worse. The more premium your buy-in, the more favourable the average expected return.
How the Bonus Buy Works
Buy Tier Breakdown
Money Train 4 offers several distinct entry points into the Money Cart Bonus:
20x stake — The base entry. You’re buying into the bonus round but with no guaranteed symbol setup. You’ll start with whatever the RNG delivers, which could be minimal or could be a strong persistent symbol combination.
Higher mid-range tiers — These options sit between 20x and 500x and typically guarantee at least one high-value persistent symbol in your starting configuration, improving your floor outcome.
500x stake — The premium buy. At this level, you’re entering the Money Cart Bonus with a significantly more favourable starting position. The RTP at this tier pushes toward the 97% end of the range. This is the buy option that experienced players target when they’re specifically chasing the game’s top end.
The Money Cart Bonus Mechanics
The Money Cart Bonus runs on a respin system — you start with three respins, and each time a new persistent symbol lands, the counter resets to three. The goal is to fill the grid before your respins run out, because a full grid triggers an end-game multiplier.
Persistent Symbol Types
This is where Money Train 4 separates itself from every other slot on the market. The persistent symbols aren’t just value tiles — they have active mechanics:
– Collector — Collects the value of symbols in its row or column on every spin – Sniper — Targets the highest-value symbol and adds its value – Necromancer — Revives symbols that have left the board – Respin — Adds extra respins to your counter, extending the session – Warp — Moves to a new position and collects along the way
The combinations of these symbols, and crucially which ones appear together, determines the scale of your win. A Collector and Sniper active simultaneously is the basis of most five-figure payouts.
Bonus Buy vs Standard Play — Is It Worth It?
Why the Buy Is Almost Essential Here
The base game of Money Train 4 is not where anyone wants to spend their time. It’s a functional trigger mechanism, but the variance between bonus triggers is extremely high, and a long base game drought is a real possibility. When the entire value of this slot sits inside the Money Cart Bonus, buying your way in eliminates the dead time entirely.
The 500x Buy: When It Makes Sense
At 500x stake, the entry cost is significant — a £1 spin means a £500 buy-in. This tier only makes sense if you have a dedicated bankroll for Money Train 4 and you’re specifically targeting the game’s upper end. The improved starting conditions justify the premium if you’re playing with correct bankroll management, meaning at least 10–20 buy attempts budgeted.
Bankroll Reality Check
Money Train 4 is genuinely extreme volatility. Even with a 500x buy, losing five consecutive buy attempts is not an unlikely outcome — it’s a statistical reality. The 150,000x ceiling exists but requires a rare confluence of symbol interactions. Plan your session budget before you buy, not during.
Where to Play Money Train 4 with Bonus Buy Not on GamStop
The UKGC’s 2019 bonus buy ban applies universally across all licensed UK operators. Relax Gaming’s full buy feature is consequently disabled on every UK-facing UKGC site. The only way UK players can access Money Train 4 with the Bonus Buy active is through offshore casinos not registered with GamStop.
Donbet is a Curaçao-licensed casino that carries Relax Gaming’s full catalogue. Money Train 4 is available with all buy tiers intact, and UK players can register without GamStop verification.
Velobet has developed a strong reputation among high-volatility players specifically because of its Relax Gaming coverage. All Money Train titles are present with the buy feature active.
MyStake covers the Relax Gaming library and processes withdrawals efficiently — relevant for Money Train players who may be withdrawing significant sums after a strong session.
Find verified, tested options at vividslots.com — our top non-GamStop casinos are checked for game library completeness, licensing, and withdrawal reliability.
Frequently Asked Questions
How many Bonus Buy options does Money Train 4 have?
Money Train 4 offers multiple tiers starting at approximately 20x stake at the low end, rising to 500x stake for the premium entry. Each tier offers different starting conditions and corresponds to a slightly different point in the RTP range.
What is the RTP of Money Train 4 with the Bonus Buy?
The RTP ranges from 96.1% to 97% depending on which tier you select. The premium 500x buy option sits at the higher end of this range, making it both the most expensive and the most statistically favourable entry point.
What are persistent symbols in Money Train 4?
Persistent symbols are special character tiles that stay on the reels once they land during the Money Cart Bonus. Each has a specific mechanic — Collector gathers values from rows and columns, Sniper targets high-value symbols, Necromancer revives expired symbols, Respin extends your counter, and Warp relocates to collect along its path.
Where can UK players buy into Money Train 4’s bonus round?
The Money Train 4 Bonus Buy is blocked on all UKGC-licensed sites. UK players can access it through offshore non-GamStop casinos including Donbet, Velobet, and MyStake, all of which carry the full Relax Gaming library with the buy feature enabled.
Responsible Gambling: Money Train 4 carries extreme volatility and the buy feature accelerates spend significantly. Set a session limit before you start. For support, visit BeGambleAware or call GamCare free on 0808 8020 133.