‌Context & Objective: With the rapid expansion of electronic communication technologies and the progressive development of digital platforms, the traditional structure of financial markets has undergone fundamental transformations, leading to the emergence of online financial markets, particularly the global foreign exchange (Forex) market, which is currently recognized as the largest financial market in the world. In this modern structure, transactions are executed through software systems without the physical presence of the transacting parties, with online brokers serving as pivotal intermediaries connecting retail traders to international networks. In Iran, despite economic prohibitions imposed on Forex trading by certain regulatory bodies due to concerns such as capital flight, a rigorous legal and doctrinal examination of these transactions' validity against the general rules of contracts in Iranian law and Imami jurisprudence (Fiqh) remains essential. The primary objective of this research is to analyze the legal impact of various online order placement methods on the validity of Forex transactions, focusing exclusively on two foundational challenges: the suspicion regarding the conditionality of the contract and the ignorance of considerations at the time of order placement. The study seeks to answer three core questions: First, given the distinct legal status of online brokers, what is the precise legal nature of the orders submitted by traders? Second, how do different types of order placement affect the conditionality or unconditionality of the contract? Third, are the severe price fluctuations inherent in global markets and the temporal gap between order submission and execution compatible with the strict legal requirement for the certainty of considerations?
 ‌Method & Approach: This research was conducted utilizing a doctrinal methodology. To gather the necessary data and establish a robust theoretical framework, comprehensive library research was employed, involving the meticulous examination of a wide array of sources, including domestic laws and regulations, authoritative texts of Imami jurisprudence, prominent legal scholarship, and relevant international documents governing the activities of online financial intermediaries. Furthermore, to accurately elucidate the technical, operational, and contractual mechanisms underlying order registration and transaction execution, the contractual terms and trading conditions of several international retail Forex brokers were extracted and analyzed, alongside the operational guidelines of widely utilized online trading platforms such as MetaTrader. Given the substantial proliferation of financial brokers and the practical impossibility of examining every existing contract, the selection of the sample was conducted purposefully, based strictly on access to the full text of contracts from brokers operating under established regulatory frameworks. This ensures that the identified contractual and operational patterns possess a high degree of reliability and can be generalized to brokers utilizing similar operational models within the industry.
 ‌Findings: The results of the legal analysis indicate that determining the precise legal nature of trading orders is inextricably linked to the specific operational model employed by the broker. In A-Book brokerage models, the broker acts as an agent, merely transferring the client's order to the market or external liquidity providers without positioning themselves as a contractual counterparty. In this framework, submitting a conditional order does not result in the conditionality of the contract; rather, it represents the granting of agency and the explicit definition of the agent's scope of authority, authorizing the broker to conclude a definitive contract once the market price reaches the predetermined threshold. Conversely, in B-Book models where the broker directly acts as the principal counterparty, the challenge of conditionality can be resolved by interpreting conditional orders as conditional offers. Under this interpretation, no binding contractual obligation is formed prior to the realization of the specified condition, granting the client the ability to modify or cancel the offer. Regarding the ignorance of considerations, the disparity between the trigger price and the final execution price caused by market volatility does not legally invalidate the contract. The final price is determined based on an objective criterion: the best available market price at the exact time of order execution. This mechanism aligns with the jurisprudential approach accepting the determinability of price to eliminate Gharar (excessive uncertainty or risk) and is functionally analogous to the established processes of price determination in auctions.
 ‌Conclusion: The comprehensive legal evaluation of Forex trading mechanisms demonstrates that distinguishing between various brokerage models plays a decisive role in assessing the validity of financial contracts. Based on the principles and general rules of contracts, the legal challenges associated with the conditionality of the contract and the uncertainty of prices can be effectively justified within the context of current market practices. Assuming the broker operates under an agency framework, conditional orders merely delineate the boundaries of the agent's authorized mandate, whereas in the broker-principal model, these orders function entirely as conditional offers accepted upon the realization of the market condition. Furthermore, reliance on the best available market price at the time of execution provides a transparent, objective, and customary standard for determining the transaction price, fully complying with the legal requirement for the certainty of considerations. In specific scenarios involving the forced closure of trading positions, relying on the legal theory of the broker's mandate to trade with themselves facilitates effective conflict resolution. Ultimately, it is imperative to emphasize that the findings of this research and the resolution of these specific legal ambiguities are strictly confined to the analyzed mechanisms and should not be construed as a comprehensive legal endorsement of the overarching legitimacy of all Forex transactions under Islamic law or Iranian legal order.