User:Qwertyxp2000 the second/Bank

"All money generated by this farm is now stored in the bank and earns 15% interest every round."

- BTD6 description

Monkey Bank is the 3rd upgrade on Path 2 for Banana Farm in Bloons TD 6. When a Banana Farm gets upgraded to Monkey Bank, the farm becomes a bank controlled by monkeys. The Monkey Bank no longer drops bananas but instead generates money throughout the round, which is placed in its very own "bank account", separate from that of other Monkey Banks.

It generates $230 per round which can be upgraded to $270 and $310 with the Increased Production and Greater Production upgrades, respectively. It can store up to $7,000 and its capacity can be increased to $9,500 with the Bigger Banks Monkey Knowledge. At the end of each round, the currently stored balance earns 15% interest. Therefore, a Monkey Bank can produce at least $265 per round at bare minimum when interest is taken into consideration.

Despite Path 3 upgrade crosspaths not seeming to be useful at increasing income, Path 3 upgrade crosspaths have utility usage. Monkey Bank with EZ Collect will highlight itself once it is full, while a Monkey Bank with the Banana Salvage upgrade will autocollect its balance when full after one round.

Unlike BTD5, selling a Monkey Bank will automatically withdraw the balance stored in the bank.

It costs $2,975 on Easy, $3,500 on Medium, $3,780 on Hard, and $4,200 on Impoppable.

Summary
Monkey Bank's main prowess comes from storing cash over long periods of time. When stored until max capacity, the Monkey Bank becomes one of the most efficient income producers in the entire game. In order to make the most of the Monkey Bank, it is best placed as early as possible but at the same time having a relatively stable long-term defense. Between Rounds 20-30 is generally the best time to start off the first Monkey Bank.

The main disadvantage of the Monkey Bank, however, is that early withdrawals harm its overall income generation efficiency. By having a good defense, the player will be able to keep the Monkey Bank's bank account stored for longer periods, for a far better reward in the long run.

Generally, one should buy more and more banks rather than purchase IMF Loan (or most other income sources, even). This is in order to capitalize on Monkey Bank's incredible efficiency, which is almost incomparable to most other income sources in the game.

Income earning per round

 * Current information provided is valid starting from Version 26.0, with the buff to Monkey City giving automatic deposits with +15% income instead of +10%.
 * For all income earnings per round in history, including current and past income earnings per round, see User:Qwertyxp2000 the second/Bank/Efficiency.

Note: The tables assume that the Monkey Bank has been initially upgraded before the first round starts and that the result is given as when the round has ended. (After interest has been applied)


 * Normal games


 * Half Cash


 * Normal games + Monkey City


 * Half Cash + Monkey City

Income earning per round with Bank Deposits
Note: The tables assume that the Monkey Bank has been initially upgraded before the first round starts, a full deposit transaction was made before the end of the current round, and that the result is given as when the round has ended. (Considering income rules and the such)
 * Normal games


 * Half Cash


 * Normal games + Monkey City


 * Half Cash + Monkey City

Additional Tips

 * 2-3-0 is usually far superior over 0-3-2, due to the 2-3-0 Bank's far greater income gain per round. With "Bank Deposits" MK, 0-3-2 is still a very viable option once a decent income flow begins, as the top path only affects the original automatic deposits, which would often become redundant compared to the benefit of automatic withdrawals from Banana Salvage.
 * A single 0-3-X Monkey Bank will reach maximum capacity at the same time as a 2-4-0 IMF Loan in almost all conditions. If you're upgrading your banks to IMF Loan, having a 0-3-1 Monkey Bank helps to indicate when all banks are full without having to check them every so often.
 * The "Bigger Banks" (+$2500 bank capacity) and "Bank Deposits" (allows deposit of cash manually into each bank) Monkey Knowledge are very important MK for maximizing the potential of Monkey Bank farming.
 * Whenever using Monkey Banks, always try pairing with Benjamin. On later upgrades, Level 5+ and 9+, he grants +5% and +12% income for banks, respectively.
 * Benjamin's "interest" buff appears to be erroneous. He apparently does not actually buff the interest rate, but rather improves the total value of the automatic deposits per round by a set percentage.
 * To calculate Benjamin's "interest" buff, multiply the current round's automatic deposit amount by 1.05 or 1.12, respectively, rather than adding percentages into the Bank's natural 15% interest. To reiterate, the Benjamin "interest" buff only affects the automatic deposits per round.
 * With the "Bank Deposits" MK, the most efficient way to earn money from Monkey Banks out of a large sum of money is to maximize the possible income interest through the new money deposit functionality. Simply deposit twice into an empty bank at the start of the round, then after 2 rounds, withdraw the cash in the bank, and repeat. For the best results, pair with Path 1 upgrades for greater income generation efficiency.
 * It is worth studying the rounds in the game, in order to prepare necessary defenses against possible difficult rounds and therefore reduce the risk of forcing out the bank investment too soon.

Trivia

 * On Version 14.0 and later, Monkey Banks and their subsequent upgrades do not make bank collection sounds when collecting their accounts.
 * Interestingly enough, the autocollection from crosspathing with Banana Salvage didn't make an autocollection sound either, even before Version 14.0.
 * The name "Monkey Bank" is a play on "money bank".
 * Although not mentioned in the patch notes, Monkey Banks with EZ Collect (or Banana Salvage) will now automatically glow upon detecting full, rather than glowing after the round it becomes full.
 * According to Ninja Kiwi's May 7th 2021 blog, the monkeys inside Monkeys Banks profit by means of investing on "quantum markets". Automatic depositing in the Monkey Bank apparently allows monkeys investing on those markets to profit even within a short amount of time of leaving their deposits in the Bank. The same should apply to manual deposits, although it will take one additional round after depositing before the interest of manual deposits can begin due to the Version 19.0 Bank Deposits nerf.

Other Sources

 * Qwertyxp2000's PDF of Monkey Bank efficiencies by version ([[File:BankBloonsTD6-23.pdf]]).