On its own, NinjaTrader Desktop runs only one Rithmic connection at a time, so two prop firms' Rithmic logins cannot both be live in one NinjaTrader; NinjaTrader's own prop-firm guide says so as of October 2026. A second limit sits with the Rithmic login itself: it defaults to one session (one direct connection for market data and trading), so the same login opened directly in a second app or on a second computer knocks one off. Several accounts under one login, or a Rithmic firm beside a Tradovate-based one, need no workaround.
NinjaTrader's own prop-firm guide (as of October 2026) allows one active Rithmic-based connection per NinjaTrader Desktop, and broker notices on the CME change that began May 1, 2020 put each Rithmic login at one session by default, with 3 or more concurrent logins reportable as professional. R|Trader Pro plug-in mode lets apps on one PC share a login but never joins two firms' logins. Two or more Rithmic firms need switching, a machine per firm, a connector add-on, or a copier outside NinjaTrader.
Can NinjaTrader connect to two Rithmic prop firms at the same time?
Not natively. NinjaTrader Desktop holds one Rithmic-based connection at a time, so a second firm's Rithmic login cannot connect while the first is running. NinjaTrader's prop-firm connection guide states: "Only one Rithmic-based connection can be active at a time; you'll need to disconnect and reconnect when switching between Rithmic-based accounts."
The limit counts logins, not accounts. A Rithmic login is the username a firm issues for Rithmic's order and data servers, and add-on vendors who document the limit say several accounts under one login share one NinjaTrader connection. The conflict starts when you spread accounts across several prop firms, so first check if your accounts share a username.
Neither popular fix lifts it. Multi-provider mode adds other providers but, as the add-on vendor PropFirmConnector notes, "does not override the documented Rithmic connection limit". Nor does downgrading: per Affordable Indicators, "On its own, NinjaTrader 8.0.28.0 holds one Rithmic connection at a time, the same as 8.1." That build, from April 27, 2023, misses every later fix.
Why does NinjaTrader say Rithmic already has a running connection?
That message means NinjaTrader refused a second Rithmic connection because another is already running in the same NinjaTrader; disconnect the first and the second can connect. It is one of two separate limits, each with its own symptom.
- NinjaTrader's adapter limit: refused at connect. Affordable Indicators' help page (August 2026) gives the wording as "Provider 'Rithmic for NinjaTrader Brokerage' already has a running connection", and the old connection keeps running.
- The login's session limit: dropped after connecting. A working connection falls because the same login opened elsewhere. A trader's NinjaTrader log, posted on the Optimus Futures community in September 2020, reads "Disconnect enforced by broker or 2nd login to the same account", and Quantower's Rithmic help page calls the clash a 'No handle' error.
The drop message is not proof of a double login: in that 2020 thread, the trader's prop firm "confirmed that in fact, the disconnect was from their side". Affordable Indicators' line that "The limit is NinjaTrader's, set on NinjaTrader's own Rithmic connection" holds for the refusal, while the session cap belongs to the login and bites in R|Trader Pro (Rithmic's own trading app), Quantower or on a VPS as well.
How many sessions does one Rithmic login allow?
One, by default. Edge Clear's notice on the change that began May 1, 2020 says CME Group requires that a trader "set up with 3 or more concurrent Rithmic logins be reported as a professional market data subscriber", and brokers such as Edge Clear cut default market-data sessions to one. An Optimus Futures support reply from November 2021 confirms that "all Rithmic accounts by default are limited to 1 connection at a time without the use of the R Trader Pro plugin."
Edge Clear defines the unit: "A concurrent login is the number of direct connections for market data and trading on your Rithmic ID." At brokers that bill per session, each extra session adds a set of data fees (see market data fees on a funded account). No Rithmic-authored page could be loaded, so these limits come from brokers, firms and platform vendors.
Session counts for four setups on one login (the app mix is illustrative):
| Setup on one login | Market-data sessions | Against default 1, threshold 3 |
|---|---|---|
| NinjaTrader, Bookmap and R|Trader Pro logged in directly, one PC | 3 | Needs Max Session Count 3; at the professional threshold |
| The same three apps through plug-in mode | 1 | Fits the default |
| Plug-in mode plus the same login on a VPS | 2 | Needs a raised Max Session Count or a second login |
| Three direct logins plus a VPS | 4 | Needs Max Session Count 4; above the threshold |
Computed by Phoenix Technologies; method: 1 session when apps share R|Trader Pro in plug-in mode, otherwise 1 per app, plus 1 per other machine on the login. A forgotten VPS turns a clean plug-in setup into 2 sessions. An Optimus Futures answer from January 2020 saying live accounts could have up to 10 concurrent logins predates the change.
What does R|Trader Pro plug-in mode solve, and what does it not?
Plug-in mode lets several apps on one computer share one Rithmic login through R|Trader Pro, counting as one market-data session; it does not merge two logins and does not reach a second computer or a VPS. It dates from the May 2020 change, with one condition, in Optimus Futures' words in April 2020: apps must "run on the same machine as R | Trader Pro."
R|Trader Pro must stay open with Allow Plug-ins on, and moving a connection between plug-in and direct mode needs a NinjaTrader restart, per Leeloo Trading's plug-in mode page.
The catch most guides miss: plug-in mode collapses market-data sessions, not necessarily order sessions. Edge Clear gives "a session count of 1" for market data, then adds: "Your Max Session for Orders will need to be set to the number of third party apps you wish to connect to." If two plug-in apps send orders, ask the firm if its order setting allows two.
A VPS vendor's guide published October 5, 2026 says plug-in mode allows multiple Rithmic connections at once. Not for two firms: Copilink's guide says accounts "must all be under the same Rithmic login, or you'll need separate Plugin Mode instances for different logins", and NinjaTrader still holds one Rithmic connection either way.
Can you use one Rithmic login on two computers or a VPS?
Only with a second session, which the firm or broker must grant and, where a price is published, charges for. The same Optimus Futures reply says "The R trader pro plugin does not work across multiple PCs though", and that a second computer means paying data fees twice; a VPS is a second computer.
Leeloo Trading, the only firm we checked that publishes a price, charges $37 a month for the secondary login access needed to trade on two computers at once, as of October 2026 (page modified October 2024), or $444 if bought for 12 months. Check your firm's current terms before buying.
Topstep's help center states, as of October 2026: "The use of VPS, VPNs, and remote servers is prohibited by Topstep's Terms of Use." That article covers TopstepX, Topstep's own platform, but at least one Rithmic firm bans a VPS too: as of October 2026, TradeDay's support page says "TradeDay does not allow the use of virtual private servers (VPS)". Read yours before you decide if you need a VPS.
Can a Rithmic firm and a Tradovate firm run together in NinjaTrader?
Yes. With Multi-provider mode on, NinjaTrader holds one Rithmic connection beside Tradovate-based connections, which use a different connection type. NinjaTrader's help guide says it supports simultaneous connections "to different connectivity providers, and in some cases, to the same connectivity provider", and CrossTrade's guide confirms "Multiple Tradovate connections can run simultaneously".
The catch is your ATMs (Advanced Trade Management, NinjaTrader's feature that places a trade's stop and target and moves the stop). NinjaTrader's Multi-provider help page says enabling Multi-provider moves anyone on server-side ATMs (a beta) to local ATMs, and notes: "Server side ATMs are only available for the NinjaTrader connection." Once a Rithmic firm joins, every breakeven and trailing move on both firms needs your PC connected.
Copying across Tradovate, NinjaTrader and Rithmic covers running one strategy over both.
Which workaround fits two, three or four Rithmic firms?
Four routes work, trading hardware against how many firms stay live: switching, one machine or Windows user per firm, a connector add-on, or a copier outside NinjaTrader. The table counts each firm as a separate Rithmic login.
| Rithmic firms | Switching: machines, firms live | Machine or Windows user per firm | Connector add-on: machines, firms live | Copier outside NinjaTrader: machines, firms live |
|---|---|---|---|---|
| 1 | 1, 1 of 1 (100%) | 1 | 1, 1 of 1 | 1, 1 of 1 |
| 2 | 1, 1 of 2 (50%) | 2 | 1, 2 of 2 | 1, 2 of 2 |
| 3 | 1, 1 of 3 (33.3%) | 3 | 1, 3 of 3 | 1, 3 of 3 |
| 4 | 1, 1 of 4 (25%) | 4 | 1, 4 of 4 | 1, 4 of 4 |
Computed by Phoenix Technologies from NinjaTrader's one-Rithmic-connection rule; method: switching keeps 1 of N firms live, separate setups need N machines or Windows users, an add-on holds N logins in one NinjaTrader, and a server-side copier needs only the machine you trade the lead on, with followers on its servers. At 3 firms, switching leaves 2 of 3 dark; the other routes keep every firm live and differ only in where the extra connections run.
- Switching. Free and native, one firm live at a time. NinjaTrader says disconnect and reconnect; CrossTrade's guide (modified October 1, 2026) adds a NinjaTrader restart, which no other source we found requires except when changing plug-in mode.
- One machine or Windows user per firm. Every firm stays live, at the cost of hardware and screens. Only an add-on vendor we found describes the Windows-user method, and we found no NinjaTrader statement on supporting it.
- Connector add-on. Third-party connectors run several firms' Rithmic logins in one NinjaTrader 8. Support depends on the vendor, and each login still uses its own session.
- Copier outside NinjaTrader. You trade the lead in one platform, and the copier places matching orders through its own connection to each follower, outside NinjaTrader's adapter. Thor, which Phoenix Technologies makes, works this way 24/7 from cloud servers and lists Rithmic among its 12+ supported platforms.
Any copier carries two caveats. By Edge Clear's definition every direct connection on a Rithmic ID counts toward that login's sessions, and we found no firm or Rithmic page on how a server-side copier's connection counts, so ask the vendor and the firm. And a copier sends the same trade everywhere, must be allowed by each firm's rules (setting up copying across prop accounts) and must never leave two accounts in opposite positions, which firms police as hedging across prop accounts.
What happens to your open orders when you disconnect to switch firms?
Orders already at the broker keep working while NinjaTrader is disconnected, including resting entries, stops and targets; what stops is everything NinjaTrader runs on your PC: ATM breakeven and trailing and simulated stops, while NinjaScript strategies hand over to their connection-loss handling after 10 seconds by default.
Top One Futures' help center says "ATM logic is fully client-side" while sent orders "are now on the server, so they stay active"; it writes about Tradovate-backed accounts, and NinjaTrader offers server-side ATMs only on its own connection, never on Rithmic. NinjaTrader's simulated stop orders "are held and simulated locally on your PC", and with DisconnectDelaySeconds at its default of 10, any strategy on the firm you leave whose connection-loss handling is set to Stop strategy is stopped by 10 seconds into the switch, because that firm stays disconnected until you switch back.
Disconnecting cancels nothing at the broker, which cuts both ways: in the 2020 Optimus Futures thread, resting orders in play during the disconnect blew the trader's evaluation (the firm later restored it). No source we found says whether the OCO link between a bracket's stop and target sits at Rithmic or in NinjaTrader meanwhile, so check that both legs show as working at the broker before you switch.
Illustrative numbers show the cost. You are long 1 ES at 5,000.00, stop resting at 4,996.00, with an ATM set to move it to breakeven at 5,002.00. During a 20-second switch, price touches 5,002.50, then falls and fills the stop, while a NinjaScript strategy would have hit its default delay at 10 seconds. The loss is 16 ticks x $12.50 (ES contract specs) = $200 per contract, or $600 on 3 contracts, where a connected ATM would have moved the stop to 5,000.00 for $0 before costs. Here the drop came inside the 20 seconds of the switch itself; in practice the firm you leave stays unmanaged for as long as you trade the other one.
The resting stop still capped the loss at plan; orders held at the broker matter more than the software watching them. The rule: switch only when the firm you leave is flat or sits behind a broker-held stop you would accept as the exit.
Which Rithmic setup should you use?
One login needs nothing, one login in several apps needs plug-in mode, and two or more firms' logins need switching, separate machines, an add-on or a copier outside NinjaTrader.
| Your setup | Native? | Symptom if forced | Route | Tradeoff |
|---|---|---|---|---|
| Several accounts, one firm, one login | Yes | None | One connection (to copy between them, a built-in firm copier) | None |
| One login in NinjaTrader plus Bookmap or R|Trader Pro, one PC | Not with direct logins | A connection drops | Plug-in mode | R|Trader Pro stays open; order sessions may count per app |
| One Rithmic firm plus Tradovate-based firms | Yes, with Multi-provider | None | Multi-provider mode | ATMs run locally |
| Two Rithmic firms in one NinjaTrader | No | "already has a running connection" | Switch, add-on, machine per firm or copier | Switching leaves 1 of 2 dark |
| Three or four Rithmic firms | No | The same refusal | Add-on, machine per firm or copier | Switching leaves 2 or 3 dark |
| One login on a desktop plus a second PC or VPS | Only with a second session | A connection drops or fails ('No handle') | Second session from the firm | $37 a month at Leeloo; some firms ban VPS |
If a connection drops and nothing else holds the login, ask the firm. Before funded size, run the setup on sim or micro size; testing a copier before live lists the checks.
Go deeper
- How to Copy Trades Across Platforms: Tradovate, NinjaTrader, Rithmic & ProjectX (2026)
- How to Set Up Copy Trading Across Multiple Prop Firm Accounts
- Do You Have to Pay for Market Data on a Funded Account?
- Trading Multiple Prop Firms at Once: Diversify the Firm, Not Just the Trade
Frequently asked questions
Does a direct NinjaTrader connection to Rithmic need R|Trader Pro running?
No, only plug-in mode does, and there R|Trader Pro has to be open and connected before NinjaTrader connects, per OneUp Trader's setup guide. With a direct connection, keep R|Trader Pro logged out of that same login, or the two compete for its one session.
Does the regular R|Trader work as a plug-in hub?
No. MotiveWave's documentation says the regular R|Trader will not work for feeding other platforms; only R|Trader Pro does. MotiveWave describes R|Trader Pro as Rithmic's free software for feeding data to several platforms without paying multiple platform fees.
Which trading platforms support Rithmic plug-in mode?
Only platforms built to connect through R|Trader Pro. Leeloo Trading's help page names NinjaTrader, Bookmap, Jigsaw and ATAS and notes that not all platforms offer it, and MotiveWave documents its own R|Trader Pro connection. Each one has to run on the same computer as R|Trader Pro.
Will NinjaTrader add support for several Rithmic connections at once?
We found no date or roadmap entry from NinjaTrader for it, and an old NinjaTrader forum thread on the topic now returns an error. Plan around the current one-connection limit.
Who can raise the session limit on a Rithmic login?
Your broker or prop firm, not you. A 2020 Optimus Futures support reply names three fields in Rithmic's R Manager (Max Session Count, Max Session Count for Orders and Max Session Count for Market Data) and warns: "If you need more than 2 concurrent logins, you will be charged as a professional." Firms that sell an extra session set the price themselves, as Leeloo does at $37 a month.
Which data feed do charts use when NinjaTrader is connected to Rithmic and Tradovate?
The first provider you connected, by default. NinjaTrader's Multiple Connections help page says real-time and historical data come from the first connected provider for the instrument type, so the order in which you connect decides which feed your charts show. Connect the feed you want for charting first.
Can other people who use NinjaTrader on my PC use my multi-provider connections?
Yes. NinjaTrader's Multi-provider help page warns that configured Multi-provider connections will be available to any user that connects to NinjaTrader on your local computer. Avoid configuring prop-firm connections on a shared machine.
How long does a dropped Rithmic session take to clear?
We found no firm or Rithmic page that gives a figure. If the login keeps dropping or refusing, close it everywhere it may still be open, including R|Trader Pro, another computer, a VPS and, per one add-on vendor's checklist, the firm's own web or mobile platform, then try again. If nothing else holds it, ask the firm, which controls the login's session settings.
Do Rithmic evaluation accounts follow the one-session default?
At Leeloo Trading they do: the firm states that evaluation credentials "will only allow you to connect to one platform at a time". Other Rithmic firms we checked do not publish their default session settings, so ask yours before running two apps or two computers on one login.
Sources
- NinjaTrader (n.d.), How to Connect NinjaTrader to Your Prop Firm
- NinjaTrader Help Guide (n.d.), Enabling/Disabling Multi-provider Mode
- NinjaTrader Help Guide (n.d.), Simulated Stop Orders
- NinjaTrader Help Guide (n.d.), DisconnectDelaySeconds
- Edge Clear (2020), Rithmic CME Market Data Subscription Fees
- Quantower Help Center (n.d.), Rithmic Issues
- Leeloo Trading Support Portal (2024), B. Explaining the plug-in mode feature
- Topstep Help Center (2026), TopstepX API Access
- Top One Futures Help Center (2026), Using ATM Strategies in NinjaTrader Desktop
- Optimus Futures Trading Community (2021), Simultaneous login with Rithmic paper trading account
- Optimus Futures Trading Community (2020), Rithmic Disconnect Enforced by Broker- not sure why
- Optimus Futures Trading Community (2020), Rithmic Market Data Billing Update and how to Avoid Professional Fees with Concurrent Logins
- NinjaTrader Help Guide (n.d.), Multiple Connections
- TradeDay Support (2026), Using a VPN, VPS, or IP masking add-on