"The dollar weakened over investors` expectations that The Fed would not raise its rate in January, and its prospect of the dovish rate policy this year," he noted here on Monday.
Mikail has forecast that the rupiah would appreciate to Rp14,000 to Rp14,090 per US dollar on Monday.
The Indonesian rupiah on Monday has strengthened by 48 points to Rp14,038, from Rp14,093 per US dollar at the Jakarta Interbank Spot Dollar Rate (Jisdor).
The US dollar was forecast to depreciate against major global currencies, such as the euro and yen, after appreciating for three weeks in a row.
Meanwhile, the expectation that The Fed would hold its rate hike might help the US stock market to move in the positive area.
Mikail said those external factors from the US economy would push capital inflow to Indonesia`s stocks and bonds market as well as help to strengthen the rupiah against the US dollar.
From domestic sentiments, economist from Samuel Assets Management Lana Soelistianingsih noted that the rupiah`s appreciation was pushed by Indonesia`s central bank, Bank Indonesia`s forecast that the inflation rate would be relatively stable in 2019.
Up until the fourth week of January 2019, the inflation rate was recorded at 0.49 percent (year-to-date), or still lower than the inflation in January 2018 at 0.62 percent (month-to-month).
However, Soelistianingsih warned that inflation might rise up in the third quarter of 2019, following a hike in the administered electricity prices. Nevertheless, the inflation rate seems able to be managed to move around in the target level of 3.5 percent, give or take one percent.
"The rupiah`s appreciation today will go forward around Rp14,050 to Rp14,090 per US dollar," she added.
Reporting by Citro Atmoko, Azizah Fitriyanti